Sorry for the hash words I said. The way I feel it is that your mom herself has very strong personaility, you have to understand why she had the attitude, probably she thought she failed her first son, couldn't give her son a better life, future and all that, man, that's heartbroken feeling for a mother.
She expects you to be a very strong figure to face all the challenge since you are the healthy child, she gave some hard feelings to you, please understand her, somehow you are her only brightness in long period time. If she felt you are weaker than she ever expected, she went a little nuts, being a senior, let's give her the right and credit to do so, again, please understand her more, with all the patience and love you got.
Even she would never change again to meet your expectation, so be it, she is mom, she had enough in her life, let her happy from now on, free of worrisome, burden, others' feeling towards her...
you take care your own child, and you may understand more.