i know it feels like it at the moment, but ending everything really isn't the answer.
i'm not gonna lecture you on how 'you have so much to live for' and 'the best is yet to come' blah blah blah but really, you have to keep going because you just do.
no matter how bad/futile things feel at the moment, it honestly doesn't mean that things will always be this way. it might last a little while, and it might last a long while, but it really won't be forever.
that's awful that you're parents aren't being helpful, but perhaps (deep down) they're terrified and just don't know what to do? perhaps they don't want to admit that their child has a serious problem? i'm not saying that's right, but what i am saying is that it doesn't necessarily mean that they don't care/you aren't loved.
the best thing you can do for yourself at the moment is just to take care of yourself and do whatever it takes to get better. be honest with everyone around you, especially your keyworker - who you do deserve because you wouldn't have one if you didn't. now probably isn't the best time to be looking for a job if you're going through severe depression/psychosis, but once you've got the help you need, you'll be able to re-evaluate things and decide what you want to do. you are unpredictable now, yeah, but that's because you're going through a lot. it doesn't have to be a permanent thing.
you never know, if you get the right help and manage to get through this then you might find yourself with a great new job/friends/interests a few years down the line, and you could be so much happier than you are now. obviously it's not guaranteed, but you'll never know if you give up. please hang in there and seek the help you need.