Much like you, I'm a high functioning autistic person who mostly can "pass" as neurotypical. I've never had any meltdowns to the degree that you have, but I have spent a lot of time dealing with the social fallout from the side effects of autism that I do experience. I have found 2 things to be particularly helpful when dealing with this fallout.
- Explaining how autism affects me
- Having and advocate on my side
Explaining how autism affects me
As I explained in this answer
People have a tendency to expect certain social behaviors (such as the spouse of a family member coming to family functions). If someone knows that a person has autism (or some other diagnosis that causes them to have atypical social behaviors), it's been my experience that they will be more likely to alter their social expectations accordingly.
In your case, the behaviors that they expect are that you don't do all of the things that you've mentioned that your meltdowns cause you to do. You aren't going to be able to stop the meltdowns or the behaviors they cause, but you can help people understand why they happen. The typical way that I do that is by explaining how I am affected by autism. Because autism is such a wide spectrum, just telling people that I'm on the spectrum doesn't do much good because it gives little to no context of what challenges I actually face. Instead, I explain to people that my brain processes sensory information differently than most people, and I give analogies to illustrate what that is like (my personal favorite is to liken the brain to a circuit that can blow a fuse if it overstimulated).
A few years ago I wrote a blog post where I explained the challenges that I faced due to my autism. When I shared it, I had messages pouring in from friends, family, co-workers, acquaintances, etc... They all said basically the same thing.
Oh, I never knew that you had to deal with all that. I'll try to remember that in the future.
There are two ways to approach this. You can take a proactive approach and tell them before hand about your autism and the potential for meltdowns, or you can return after the meltdown is over and explain what happened. The proactive approach is more likely to be successful the closer you are to someone, so I would recommend only using it with close friends.
Having an advocate
Another really great solution to help with the social fallout is to have another person who can advocate for you. I had this happen quite by accident a few years ago, but it turned out really well. I have a lot of sensory issues related to food. This has caused me some hassle throughout my life and I've had several people express the desire to avoid eating with me because of it. I had a coworker a few years ago who took it upon herself to educate some others about my sensory issues on my behalf. This helped the others be more accepting of my different behavior.
The reason for this is social proof, which is
a psychological and social phenomenon wherein people copy the actions of others in an attempt to undertake behavior in a given situation.
Research has shown that the actions of a group have impacts on individuals within the group that last even once the individual has left the group.
When two or three individuals within a group give their judgments in the presence of each other (group situation) the whole group establishes a range and point of reference peculiar to the group. A norm once established in a group situation persists in an individual member even when he faces the same situation alone subsequently.
You can take advantage of this phenomenon by having someone who can advocate for you. Find a friend or two who you are frequently around and that you can trust to be your advocate. Explain the issues you have to them and ask that if they see you having a meltdown they help explain to the others around that you what is happening. If they display acceptance and accommodation of your situation, then social proof will lead the others to be more likely to follow suit which will lower the negative fallout.