I am trying to come up with this sentence, but I feel like some parts of it are too literal and idiomatic, and some words I used here are new to me, so maybe I made some poor decisions when picking them. Could you help me with that?
"Sometimes I feel like most people only think about themselves. If they need your help, they'll contact you. If they don't need it (if you're not useful to them) they won't contact you at all, like they don't care(it's not their business)"
I feel like "think about themselves" is idiomatic and i'm not so sure about the usage of "useful" here.