I hate my mom and can't wait until she dies and the only reason I talk to her is to keep my inheritance assuming there even is one.
That sounds like a mean thing to say. I assume there is a reason for you feeling for strongly about her?
I'm sick and tired of her.
It is wrong for you to pretend to like her just to get an inheritance.  That is really poor form.
It's what I have to do to keep my inheritance.
You need to find a way to work to fix the relationship. You can't just use her like that and just pretend to like her.