If your mental health issues require you have a guardian ,there are group homes and assisted living facilities that take your check and give you an allowance ,,but you are somewhat on your own ,you have a guardian you choose ,but your getting your feet wet at living on your own .
If you don't need a guardian ,there is vocational rehab
they will train you for a job and help you find one after training ,
If you don't have an actual disability
The state (I am telling you about things in the US ,but I am aware other countries 18 does not mean you can just move out or there are programs to help you become self sufficient)
But in the US there is also work force
They will pay for you to go to a vocational school /college
to train you for all kinds of things ,
What is the reason your over 18 yet your parents have so much control over you ?

wtf controlling your bank account is straight up exploitation but same it’s so frustrating to live with my parents and having to put my life on hold bc I can’t do anything 🙄

Good luck