Stay strong and don't doubt yourself. He will be a master at pressing buttons to make you second think your sanity no doubt, so stand strong. The fact that your only friends are his relatives is classic in these situations, they isolate you from anyone they can't control. I lived with a controlling, emotional abuser for 20 years, I still feel shame in admitting I did it for so long. But he had me convinced I was everything bad and he was amazing for putting up with me. Everything he did was perfect and I was greedy, irrational and expected too much....I know now that was never the case.
He also did the disguised help things, it took me some time to really get enough confidence to trust myself and realise he did nothing unless it was to benefit him and his needs. Don't take responsibility for him, don't try to fix things or cover for is not your job, he is a grown up and has to take responsibility.