I'm going away to college and my relationship with my mother is going bad...?

I will be 18 years old next week. I have never been very close with my father. It used to really bother me that we never get along but in the past few years I have begun to except it and have decided to work that much harder on being close with my mother. But lately my mother complains about me all the time and acts like I never do anything right. When I try to help out with something like washing dishes or doing laundry or cooking, instead of thanking me she just complains about the way I did it. All through dinner she complains about her job or how no one helps her with anything, which isn't true. This morning I slept a little late for school and she yelled at me more than she ever had before. I was still on time for school, but said some things that really hurt me, like "I can't believe you turned out this way" and "you're lucky this door is locked or I would hit you". Things that I tried to brush off but actually bothered me. She threatened to not help me get college loans, saying that I don't deserve it. But I can honestly say that I am a smart, respectful, mature high school senior and I don't give my parents hardly any trouble. I don't do drugs, I don't have "bad" friends, I haven't been arrested, I get good grades, and I hardly ever complain. My mom seems to think that taking care of me is such a chore and I really don't think she realizes how easy she has it compared other parents with trouble-maker teens. Part of me wants just ignore all the negative things she says and move on, but part of me really wants to patch things up since my relationship with my dad isn't good. Also, I really need them in order to go to college and move out which is only 6 months from now and I don't want them to feel used. What should I do?