My brother says I'm worthless

Okay just for a little more context. I live with my parents, older brother and little brother. My mom just got out of the hospital for heart failure. My younger brother is the "Smart* one and my older brother is the successful one who makes good money at a corporate job. Out of my entire family I'm the only one who's unemployed and doesn't drive. I'm on SSI and Medicaid. I'm the one who takes care of our cat. I'm pretty much a loner who volunteers with animals/ cares for our cat. Outside of that I'm pretty much useless. He admitted that the only reason I'm not homeless is because mom would be heart broken. He only deals with me because of our mom tbh. He hates that I'm pretty much worthless especially since I had so much potential to be something one day. ( I've been unemployed for 9 years and people ask me if I'm autistic sometimes)

The other day he had a hard day at work so I decided to buy him some pizza. The next day he confronts me about how I contribute nothing to our mom getting better. He said he saw me sleeping next to her at night while she was awake when I was supposed to stay up with her all night. Our mom has a hard time sleeping because she struggles to breathe at night she said she was happy I was there with her but now there's going to be a family discussion about how little I contribute to anything and how I can be useful I guess.

This completely came out of the blue and I'm almost starting to regret buying him anything. The only problem I'm having is my mom said she was fine last night and he just came at me randomly calling me worthless and wanting to give me different household roles.

I mean I do help with rent, cleaning, caring for cats but I only help with rent because of my SSI and everyone else works.

I just don't know what to do anymore.