I'm 18 and I live with my parents, I also have two younger sisters. Ever since I was younger until now nothing changed in terms of their parenting with me. I have to go to bed at X hours and many other things that takes out my autonomy. (it's kinda embarrasing have to end a conversation with someone because your mom orders you to go sleep at 11pm..). This occurs, I guess, because my parents want to give equal parenting to me and my sisters. But that's not the point (maybe for another question?).
Note: It's money that my family gave me and money that I collect for future things and can't go into my pocket basically. I don't have a bank account (and opening one isn't probably a solution because I'm not looking for a job right now).
As usual we buy things for ourselves, I, being a technology lover, likes to get something new from time to time. The big deal is: i have my savings stored in a moneybox, BUT, that moneybox is hidden somewhere in the house and I don't have access to them. To use my cash I have to request my mom for that and with detailed information of "what's the money for?". As you might ask, this is awful and even when she accepts my request she asks a million times "is it worth it?". And sometimes it could go very wrong, like in the incident 1.
I saw a sale for a game "Rocket League" and I decided to buy. Asked my mom and I get the usual questionary of the cash. She gave it to me the money I needed after a long discussion. A few hours later I saw that if I spend 5 euros more I get some DLC's which is a great deal. When I said to her that I need the extra she got all pissed off (yes, she got pissed for 20€ to spend on a game). Since then I really don't ask for anything else except on the holidays or something.
With these rules I can't simply buy condoms for the reason that she will ask me awkward questions about it and it sucks. So, since I'm 18 now and I don't want to be treated any longer like I'm 13, how can I tell my mom that from now I can/should manage my own cash?
(Feel free to edit my question if something is misspelled or if I'm not being clear enough, thanks)