Since my dad passed away 2 years ago, my mother takes everything out on me. She is mean, gets mad and won't talk to me. Advice?

So her sister moved in with her about 10 months after my Dad passed. She is not nice to her at all. She goes through mood swings. Where she is nice to her but then she finds something wrong with everything she does. Same with me. She is a near freak and worried that we are going to ruin something in the house. Everything is this is my house. I do everything for her. She will go nowhere since COVID. She does have a heart condition and a blood disorder. She is very hard of hearing. I cannot agree with my Aunt or that starts a whole big issue. She is very childish. Like you don't care about me you treat her better. She acts jealous of many things. she is poor me. She was never like this prior to my Dad's death