I need help with my Mom

I can't tell if I'm a bad person or if my mom is manipulating me. Over the years she has hit me for being sick, told me her health is worse than mine and I have no room to complain, and tells me all the time everyone in my life is a narcissist BUT her. She also buys me things I don't want or need and gets mad if I am not "happy enough" - I can never be enough for her and it feels awful - but I'm worried I'm really not enough and she is right.

She is always borrowing money even from me, and she always says she will get a job but she hasn't had a job since I was little. She constantly tells me I remember things wrong and that feels weird -

I could go on and on about all the things she has done, but every time I get upset she has some kind of reason why it's not her fault and I am just trying to manipulate her, it's like she is never to blame for anything and I can't tell if that's because it's my fault?

I live a physically comfortable life, food on the table, a nice room and the space to be my own person. My issue is that everything I do my mother hates and I am doing wrong. 

Recently my health has gotten worse and I was advised by a nurse to go to the ER, my mom and I got into a huge fight because "I have all those symptoms too and there is nothing wrong with me, you just have to suck it up and stop being dramatic" (My moms words obvi) 
The nurse said I may have untreated diabetes and that I need help but my mom just asked to use the family car (That my grandma pays in full for) to go to the gym instead because "I don't really need it"

I DON'T KNOW WHAT TO THINK - I would like a third point of view on this