Caught Myself Cheating After Divorce...

I was married for ten years and just got a divorce. I feel so ashamed but I had this fantasy about someone from school, my ex's colleague, let's call her Jane... We were drinking one night, talking and laughing like old times. Then it happened, we ended up alone, with me practically seducing her... Even though I'm still adjusting to being single, part of me feels relieved for letting that happen but mostly just disgusted by myself.