having trouble living with grandpa

we fight sometimes. he is not an easy man to hangout with. very closed off emotionally, and arrogantly intelligent, which makes it difficult to get along with him.

since moving in with him, about 3 years ago, i have realized he has many characteristics i despise in people: dishonesty, arrogance, and closed off emotionally.

we have a symbiotic relationship, i pay for all of my end of things and utilities while having a home to live in, in exchange for me being there for him when he needs me. he takes care of himself completely though: drives, cooks for himself, baths, etc as a 93 year old.

the problem is he is critical of me, never supportive or encouraging, just criticcal of me being a "boy" or "kid" and this bother the fuck out of me. he is just a bully tbh and i have trouble being around people like him. i have lived enough and been around enough to know my own worth.

what is any advice you have for me? tell me what i am failing to see please. tell me what i dont want to hear.