When women have sex with men, they form a bond that men don’t seem to form with women they have sex with in the same way. It’s probably biological, but regardless, you’re hooked. You’ve been together 3 years, which is a long time, and admittedly, most of your high school career now. This makes it even harder to move on.
But if you’re so upset that you’re crying and fighting a lot, it sounds like you need a change — to see what else is out there for you. High school is a great time to sample life, as is college. Rather than get stuck in a rut with someone who you love, but have doubts about, you need to find a way to play the field. It would be very convenient to do this when school starts and he goes off to college. But you may not be able to wait that long. My guess is that the fighting and crying are going to get worse if you don’t move on.
You ask how to get the power back in the relationship. Well, you can’t control him, but you can control yourself, and by being true to yourself and doing what’s healthy and right for you, that will give you back the power, period. Ironically, if he sees you getting your act together and moving on, this may very well propel him to change in a way that values you and your time more. When he sees that you’re there for him at his beck and call, that you take his obnoxious behavior when he drinks without any consequence, and that you are home waiting for him while he’s out with his friends on Saturday night, he’s just going to do more of the same. If you change the pattern, he may react by changing his, too.