ATTENTION DIVORCED MEN AND WOMEN THAT HAVE ALREADY REMARRIED!?

I was married for 16 years (together 19 years) to my High School Sweetheart. We have 3 children. We had an excellent marriage and very successful. I found out in our 13th year of marriage that he had a bad sex addiction. It included movies, magazines and hookers (I've been checked repeatedly and I am clean, thank God) He had the addiction before we met. I am very observant but never knew because it was 20 minute hookers and not affairs. He worked a earlier shift and got out 2-3 hours earlier each day. He was home every night and every weekend, so it was easily overlooked. When I had finally found out, by mistake, he admitted it all. I stayed by his side through a few years of counseling. He failed and we divorced. I met a great guy and I am newly remarried (2 years). I constantly feel lost in this marriage and wonder, every day, if we could reconcile. I have a great marriage and I believe the feeling stems from believing my rightful place is with the family I had created (I do have custody of the kids) and it includes the ex. He is not remarried but dating. Have any of you gone through this and what did you do to get past the feeling of deep sadness and curiosity of "what if"?