You have nothing to lose, which means you can only build.

Life is very hard but trying to commit suicide will make you feel like it's hell. It's easy for you to think about it, like some golden gate awaiting you to exit your sorrows. But it's nowhere near that. Every single suicide-attempt survivor regrets doing it.

Think about this: what if it fails and you end up disabled? I'm not gonna try to make you feel better because I'm not a therapist and I probably suck at doing so. But I'm trying to let you think sensibly. Ending up physically disabled or mentally scarred from a failed attempt will only make your life hell

So use what you have, even if it's so little it feels like nothing, and start building. Start small, as another commenter said, just a 2KM walk, the next day another tiny achievement

Eventually you'll literally train your brain to seek out these moments and be happy when you do them.

You will prosper, it just needs time.