What you are feeling is very, very normal. You've dealt with so much over the years and now that he's wanting to return to the marriage has you second guessing what you want to do. Take all the time in the world to figure out what you want. Maybe make a pro and con listing of whether to stay in the marriage. Sometimes when we write down the pros and cons, things become much clearer.
Maybe you both need a total break from the situation. Any way that you can take a little vacation and just be on your own to think about everything without interruptions?
Hang in there!
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.