[Crossposting this in relevant subreddits, apologies if you see this twice.]

So I have (spastic diplega) cerebral palsy, bipolar type 2 disorder, complex PTSD and possibly undiagnosed autism spectrum disorder. I'm 32 and on SSI. I'm admittedly fuzzy on the details because I was so sick but last year after a particularly bad manic episode, my no-nonsense mother became my payee. If I want to go out shopping for clothes for myself--or anything, really--I have to call her, ask her for money in advance and provide receipts. Frankly, I'm fucking tired of this. She refuses to even give me the chance to prove that I can be responsible, but what hurts the most is when I find clothes that I--this will shock you, Mum--feel beautiful in and she refuses to consider it as a purchase. (I had to stand my ground last month just to get a nightgown I've literally wanted for years. Cosplay and historical fashion are the only ways I'm winning my self-esteem and self-respect back, but she just views it as "frivolous" and "impractical."

On a more practical note, I'm unable to get intimacy items because I'd have to go through her and at my age that's absolutely mortifying. She insists on making any purchases for me, but always makes excuses when I try to discuss my budget reasonably. I want to feel pretty and I want to buy my own clothes; at this point, I feel like a rebellious extension of her. There's probably some toxic shit in here that the rest of you can untangle. I'm so tired, guys, so tired. My dad refuses to help, by the way; he tells me to take it up with Mum.

Any help?