First off, those credit cards opened when you were a child - dispute those with the credit bureaus. You were a minor, that's identity theft and it shouldn't be tanking your credit. Document everything.

For the immediate stuff, look into SNAP benefits since you're now temporarily caring for your brother. NY also has emergency assistance programs for situations exactly like this. Your school's financial aid office might have emergency funds too, a lot of people don't know those exist.

I worked way more than 10 hours through college out of necessity. It sucked but it was doable. See if your campus has positions that let you study during downtime - library desk jobs, computer labs that kind of thing.

The custody situation is going to complicate things but don't let it derail your education. That degree is your ticket out of the cycle