First off, thumbs up to you for getting through up till now. I'm much younger than you and nothing in my life so far even comes close to what you have experienced and are still experiencing, I can only imagine it sucks a whole crapton.

You are not worthless. Someone who is worthless would not have fought and tried so hard for so long to get their life back on track. Don't give up. A year from now you'll look back at yourself and think "boy am I glad I stuck with it". I know nothing I say will be a sudden solution or fix for your problems, but hopefully it helps even in the most minute way.

Perhaps set your sights on something further into the future. Change your ToDo list from "landing this job" to say "renting out a small place for my own". Sure it doesn't actually change the situation you're in, but this way issues along the way to your goals are just hiccups, and not failure to do something you planned to. Maybe this could provide more motivation and push.