I am so so so scared of the dentist!!?

I haven't been to the dentist for over 1 year now, but I can't go back. The last time I went, the dentist tried to pull one of my teeth out which is broken, I only have half a tooth at the bottom back of my mouth. The rest of my teeth seem fine. To be honest, I don't brush my teeth that much, maybe every 3 or 4 days, depending if I'm actually going out anywhere. I'm only 17 so I know I can't avoid the dentist my whole life. I am just soo scared of it, and everytime I feel a little pain or discomfort in a tooth it makes me all stressed and worried even more thinking oh god my teeth are rotting, that might mean a trip to the dentist. I have one tooth that kind of hurts everytime I bite into chocolate or anything really sweet. I don't even eat a lot of things like that but when I do I've noticed it is only the one tooth that does it. The one that is half missing used to hurt a few years ago, and my gum swelt up and some sort of liquid came out of it. Now it seems almost fine, and it doesn't usually cause me pain or anything, but I'm worrying incase it starts again. Someone help me please, I have bad anxiety and really I would die if I had to go to the dentist I think. :(