Toothache

I have a tooth in the back that had a cavity a couple of years ago which I got fixed. The cavity was very deep though and that tooth has been sensitive since then. It has not really bothered me though because I just won't chew cold things on that side. Well, since Eliza's birth, that tooth has been bothering me. At first it was very mild. Then on Saturday, the whole right side of my face was hurting as well as about 5 teeth in front of the bad one. I couldn't even touch them with my tongue. On Saturday and Sunday both, this pain would just come and go for no reason. it wouldn't hurt when I was eating. Then on Monday and today, it has changed to just an ache in that particular tooth. I don't know what happened to cause it to hurt all the sudden. I know I need to go to the dentist, but I don't know what I want to do about the tooth. He has mentioned a root canal to me before, but I really don't want to do that. I am considering just having it pulled. Getting rid of the tooth and the pain. I've just never had either one done and I am just not sure what is best. Plus both are kinda scary to me. I've heard stories of having to get a root canal redone and the pain not going away. Also, how will it feel to be missing a tooth. I'll probably wait until I am in excruciating pain one day to go in instead of taking care of it now. I have plenty of excuses to do that. So root canal or get it pulled???