First of all...
Some of these may be obvious, but I want to state them anyway as they relate to the rest of the answer.
- You have the right to choose who you are with. No justification needed.
- You have the right to go live where you want.
- Both you and your mother have the right to refuse to talk to the other if you so choose. While this is of course not desirable, there's little that either party can do about being "blocked" by the other party, if they stick by their decision.
- You should avoid any personal relationship where the other person is intentionally toxic, intentionally uses you like an emotional punching bag when they're upset, or tries to manipulate you to do what they want (while being aware of the unethical nature of their behavior). Note that the misbehavior must be intentional for this statement to apply.
Your mother's response
She is livid that I would move out on a day that she would not be home.
While I can understand being upset about not being present when her child moves out; being livid about it is (in my opinion) uncalled for.
I tried to apologize for the miscommunication with my friend and patch things up, but she is basically on the verge of excommunicating me.
If this is something she has said/suggested/implied, and not just an inference on your part; then it sounds like she is using your feelings (wanting to stay in touch with her) as a means of getting you to do what she wants.
Analogously, when someone robs you and threatens you with "your money or your life", they are essentially manipulating you (because they know you'd want to avoid dying) and therefore choosing the other option (giving your money); which is exactly what they're after.
I tried to make it up by saying I'll get everything finished tomorrow (which won't be fun, but will be possible) and spend the entire 17th with her and family. She won't have it.
You offered a solution to the problem she pointed out. She refused. If I can take your word for it, she did not offer a reasonable explanation why your proposed solution isn't viable.
My mother said to my siblings while I wasn't in the room that "she [me] just doesn't care"
If this was after you offered to spend the 17th with her, she is flat out lying about you.
and that she's "heartbroken".
This is assuming that your description is accurate, but it sounds like she's implicitly arguing that you should implicitly change your plans based on her feelings. Combined with dismissing your proposed solution; this is starting to feel like emotional manipulation and her expecting others to emotionally cater to her without being open to compromise.
Your mother's advocate
Based on your question alone, we can't be sure that your mother's behavior is intentionally manipulative. There are many ways in which this behavior is not intentionally malevolent, such as:
- She was raised this way, and therefore is treating you the same way her parents treated her.
- She is prone to emotional and/or dramatic outbursts without meaning to manipulate.
- She is emotionally dependent on you, and is simply trying to hold on to someone's she's afraid of losing.
I can't conclusively answer this. She may simply lack emotional control (without having ill intent); or she may be intentionally using dramatic outbursts so that people cater to her whims.
What I can say, however, is that you should not rely on her self-assessment for this. She is going to claim innocence in either scenario, and it's nigh impossible to differentiate between the two based on her own words.
Try to evaluate her actions (past and present).
- Is this behavior consistent? Does she behave like this with everyone?
- Does she behave like this even when it doesn't benefit her?
- Is she capable of switching emotions rapidly when she is (not) getting what she wants?
- Has she made threats (veiled or not) about what would happen when something she doesn't approve of would happen? In other words, does she display any active knowledge about what her reaction to a possible future event may be?
- Does she have a history of lying to get what she wants?
If you're still uncertain; you could ask her how she wants you to fix it. If her response consists of nothing more than blaming you without offering a compromise/solution, or her solution is completely devoid of any compromise (e.g. telling you to not move out); that is a very strong indication that she's taking her personal dislike out on you, and there's more at play here than simply the bad timing of the move.
I just don't want to completely ruin my relationship with her.
If that is the top priority for you (even at the expense of your own happiness), and if your mother is intentionally manipulating you; then you are giving her the leverage she needs to get what she wants at the expense of your own happiness.
This relates back to the example of the robbery. Wanting to not die is a given, and therefore can be used as leverage to manipulate you into giving the robber your money (which is then the lesser of two evils).
I know I messed up,
You did not mess up. At worst, you made an honest mistake. You have explored every possible avenue to rectify the issue that your mother is pointing out.
Genuine question: if a parent is unable to forgive their child for making a genuine mistake with minor consequences (i.e. nothing irreparable); do you think they are being a good parent?
but is she overreacting?
Yes. However, that doesn't answer whether or not she is maliciously overreacting.
You can answer this better than we can. Is your mother prone to drama, regardless of whether she's trying to get what she wants? Can she be dramatic even when being dramatic is not to her benefit?
Is there anything I can do to make the situation less sucky?
If your mother is trying to manipulate you, then there isn't much you can do. In this case, the problem she is raising is merely her current method of gaining leverage on you. Even if you fix the problem; she'll look for the next justification to force your hand towards what she wants.
Even if you point out the blatant manipulation, she would never admit to it. There is little point in trying to do so. This advice comes from personal experience.
It is impossible to wake someone up when they only pretend to be asleep.
However, if your mother's behavior is not intentional, then there is indeed something you can do to make things less sucky.
I am well aware of my personal bias with emotionally manipulative parents. Forgoing my bias as best as I can; based on what you've told me, I think your mother is knowingly trying to force your hand.
Note that I only know what you have told me. In other words; the words you chose paint your mother as manipulative. There are three options here:
- Your explanation is factually accurate and she is manipulating you,
- Your explanation carries a personal bias, which would mean that you (possibly subconsciously) believe she's manipulating you.
- I am wrong. (but it's hard for me to conclude that based on my own opinion, of course)
I cannot conclusively answer this. I'm only assessing what I read in your question, while trying to avoid any personal bias as best as I can.
How to make things less sucky
This part assumes that your mother's behavior is not intentional, i.e. she is not being malicious and simply prone to emotional dramatic outbursts.
The core of the issue here is your mother's response to the situation.
However, in order to maintain the relationship between you and her; you need to be on your mother's side.
- When approaching the issue, never describe it as a her fault. Don't pit her as the opposition in this.
- Instead, try to be her ally. Offer her assistance to improve things.
- Focus on how her behavior makes you feel, rather than what she does wrong.
- Apologize for your genuine mistake. Mention that it was a genuine mistake and not intentional; but try to avoid trying to repeatedly make that case (this can come across as trying to sell her on a lie).
- Ideally, you'll want to include your siblings/father in this. Addressing this is essentially an intervention; which is much more effective when several loved ones talk to her about it openly (without accusing, judging or labeling her).