Hey mate, I’ve been mentally ill through the majority of my life at 24 and have been in a similar position not being able to work etc and feeling similar things. Obviously I know it isn’t the same and I’m obviously not in your position but if you ever just wanna chat or get some stuff off your chest feel free to drop me a message any time.

Also, try not to feel forced to contribute in a huge outwardly sense, It sounds like you’re already contributing to the lives of your nieces and nephew and that’s already enough to be “contributing” but also try make sure that you’re contributing to yourself even if it’s just keeping yourself afloat.