Mom wants to control my life! Any advice?

I have made plans to take my son 2 places this year. Once in few weeks, and then few days in June to beach. However, all she wants to do is spoil my plans. She said " you can't go 2 places in one year!" My friends you've got to be kidding. The last time I check I am a grown woman capable of making choices for me and son. I don't get to do much with my son ever because of all I do for her or taking her here & there. This whole living arrangement has became too much for me. I am so very unhappy, and she is so very selfish, and self absorbed. She doesn't even take into account or relize how much of my life has been given up to care for her. 7 years as of now. One thing that's making other options difficult is we are financially tied at the hips. I drive her car, and she makes the expensive payment. Never letting me forget. I pay insurance, and all gas. Then we bought the place we live in together. I have paid half of it also for 7 years. I geuss I need to just get a car which she doesn't want me to then I wouldn't be covering her car expensives. Lately she has been saying hurtful little comments. I believe out of jealousy, but it does hurt my feelings. Sometimes I feel like a robot in this caregiving role, and If I could go back I'd never moved in with her. Feels like a nitemare I can't be set free from.
sorry for all the venting. I appreciate all you who read this, and are saying to yourself "I totally know how she feels and know what she has been going through" I only wish I could be stronger like some of you, and break free from the chain. If I only didn't have to live with her. I'd still cook, and take her to appts. grocery shop for her, the whole nine bascically. Any suggestions or feedback is great. Depression is another part of my life that I feel wouldn't be if it wasn't for all this stress.
Thanks for listening.
Kelly:)