Thanks for writing us here. It’s time for you to have a talk with your mom, but I wouldn’t do this without being totally prepared. First, I would point out that many other 18-year-olds have gone off to college and begun living on their own, and I would find some real examples of this among people you know.
Second, have a plan to explain to mom that you need to feel more independent so that when you finally do move out you are not going to feel like you were pushed out of the nest unprepared, not having strengthened your wings.
Finally, have a plan in place about what you need for independence as a starting point for negotiation. Things like curfew and the car are good places to begin. She might fight you on this, but at the very least this will give you a starting point for discussion.
The main goal of this first meeting is not necessarily to solve all the problems, but merely to set up a meeting. The idea of having the dialogue open and regular will be important, rather than have it just come up during times of conflict.