I have mental health disabilities

I have depression, anxiety, post traumatic stress disorder and schizophrenia. I hate having these disabilities and am learning to work with them to function in life as best as I can. My parents want me on supplemental security income for the rest of my life if I can’t handle working full time. I feel really discouraged because I feel the goal should get me to be independent as possible and not reliant on the government welfare. My parents say work part time and keep the benefits.i can’t make more than $1,500 dollars per month approximately in wages. Otherwise I lose my benefits. Why couldn’t I be able to survive on 20-30 hours week of work? I feel really glum about my future .