I've been caring for my disabled brother and want to apply for caregiver benefits, who do I contact?

I don't know much about it, but I would check into a program called PACE. It's support for inhome care for seniors. Here's a link. Scroll down and you'll see it.

seniorliving/healthcare/help-paying-home-care/

It will be much more cost-effective for him to receive his care in a facility setting, so if he cannot afford to pay 24/7 care in his own home, he must go to a facility. It may seem harsh to understand that, but it is that way for anyone who needs 24/7 care. If all he needed was an alert pendant for an emergency every other year and some meals delivered, fine, he can survive at home. But if he is not safe by himself, it costs more to bring in a team of caregivers than it does to go to a facility. Best wishes for his future, and I hope you yourself can find a good job somewhere to regain your own financial footing.

He can apply for Medical Assistance and he can receive help. But there is no program to pay you for your past caregiving. Some states have a very minimal amount of caregiver pay, but it is usually such a small amount (minimum wage for 4-6 hrs a few days a week) that you couldn't live onit.