Being originally from a background and area where this is rife, I can only offer the following:
1. Change your mindset - Positive things happen to positive people, as basically they envision the positive result they want and engineer (either consciously or subconsciously) towards it. Negative people think they will always fail, hence don't try, hence fail, and vicious self-reinforcing circle repeats. This is hard to to when depressed, hence why you need to to change lifestyle as per following as example.
2. Take any job - It's not about doing something you love or pays well, but getting out of the house and changing your environment. A fresh/different perspective, new scenery, fresh air, and interacting with other (different) people always helps. It can also help you find structure and (different) routine in your life.
3. Focus on one change at a time - Thinking about everything at once can be overwhelming. Try and make one change at a time. Do the easiest (most achievable) things first. Success at them will make you feel good and help as building block to next (harder) thing.
4. Don't worry about external opinions of nay sayers - You are not in competition with others, only yourself, so as hard as it may be, focus on your path at the pace you are happy with and ignore what others say. The key thing is you keep moving forward, positively, even if only one step each day. Once you stop standing, and start moving, you will inevitably make progress, and that progress will help you move more.
5. Build income - Inevitably money is the cornerstone to fixing many problems in life, and with an income that meets your base needs, you may then be afforded the opportunity to do things you want to do, not have to. This could be something like hiring a carer a few days/hours a week so you have time to do something you want e.g. build your skills/portfolio/resume for a future step of a new/better job.
6. Do not be emotionally black mailed or feel guilt for wanting to live your life - We all have our paths to walk in this life and sadly there are people that will put you down or try to stop you for no good reason (i.e. your path is not self-destructive such as drug abuse) and its to do with what they want rather than what is best for you. No matter how hard it is to say this, or resentment parents/family may feel, but they have lived their lives and made their choices. You must live yours and make yours, even if in the immediate term it upsets people. In due time, most people realise things were for the good and the initial negative reaction such family has is more about the change itself rather than why/what change is for. One way to smooth this is to give people notice so change is not unexpected i.e. tell them you are telling them, tell them, tell them you told them, do it.