What do I do when me and my mom just aren't compatible people?

ok me and my mom never get into really big fights because I walk away, but that doesn’t mean I don’t feel extremly hurt over what she does. I am 15 and me and my mom are just at ends about everything. my grades are good but I hate her giving me praise on them because she acts like she has helped me achieve them when she hasn’t even giving me a spare pencil or pen for me to use on my homework. My biggest problems with her pretain to her and my dads divorce and just my late dad in genral. When I was little all she said was that it wasn’t always safe to go there and refused to tell me anymore. I know my dad and there is no way he was ever violent. Even today she says it’s nothing I should know. As a little kid you can imagen the things I would make up. I loved my dad so much, we look a lot alike and I’m just a daddy’s girl. I never really bonded with my mom I guess because even back then we were at ends. After the divorce and even now she would tell me the story of how my dad once pulled my hair in a store when I was 1, which I have a hard time beliveing. and how he was a and I quote “man whore” he was a u.s. marine in Korea so not only is it damaging thing for me to hear as a daughter but its blatently rude to the u.s. military. she also talks down to me in the voice you would use with a 6 or 7 year old. She also makes fun of my friends constantly (none of them so drugs or anything illegal) saying they are a bad infulence or they’re immature. so I can’t bring my friends over for sleep overs or anything. Also my mom had 4 other children with a previous husband that my dad basically raised, and they all made fun of him and my mom joined in right in front of me. I used to cry in my room every night when I heard that, also when I was 13 I began to hate my dad because thats all I was hearing was how bad he was and that is the biggest regret of my life. for 6 months I didn’t see him then when I was 14 I realized he had done nothing but be the absolutly most perfect dad in the world to me and that set me off on my mom and I just started to realize how much she had lied to me and put things in my mind. So I satrted to see my dad almost every weekend or when ever I could and my mom started to yell at me for doing so, saying she misses me too even though she gets me all week long. For as far back as I can remember, my dad has been sick with one thing or another, when I was about 2 months he has a serise of heart attacks and from then on he batteled basically everything but diabetes. when I was 14 and earlier this year I was regualting my dads pills and giving him shots (the nurse showed me how to) and when I was there things ran smoothly but I didn’t let my mom know otherwise I know she would have screamed about how I was too young. He beat this tonsil cancer, but the kemothearpy killed him on september 5th 2009 at 3:00 am he was 77 years old. He was so weak that I he couldn’t walk or talk and he had a feeding tube in. He got all his medical care but he just couldn’t win this battle after everything else he won against. when I heard he had cancer, my mom tried to make jokes about it, I just looked over at her and said ‘why the hell are you making jokes! this could kill him!’ then she said in the most demeaning tone ever ‘oh sometimes you just have to laugh.’ I have tired to be nice to her and get along but I can’t everytime I try and break down the walls between us and let my gaurd down she says something or does something that makes it go right back up. I can’t take it anymore and I need to either figure a way for her not to hurt me or I need to leave.