WHAT EXACTLY WERE THE BOUNDARIES SHE DIDN'T RESPECT. YOU JUST DEFENDED EVERYTHING SHE DID.

I was married for 22 years and now divorced for 27. What I have learned is that you have to respect yourself enough to not let another person disrespect you.. You already know that her behavior was not right. You're asking someone to tell you that your gut reaction is wrong and I doubt that it is. On the other hand,you have to ask yourself if you are a jealous person. Going at 3am to pick her up sounds like maybe you didn't trust her and when you didn't pick her up she went out with another man. Do you know for a fact that they were at Denney's?
Whether or not to get back together with her isn't the real question. Are you secure enough in who you are to let her go if she doesn't treat you right in the future?