in love with my ex?

okay so ive been with my husband just over 2 years. we are married with two beautiful babies. the person i was with before him was a girl. I was with her for two and a half years and we were engaged for well over a year. I was very happy with her but I was young and she was still a bit young herself. we were both not ready for such a "grown up" relationship and ended up parting ways. while we had been separated we still were sleeping together but also with other people. that is how I meant my husband. he was only suppose to be a 1 time thing and mid sex he asked me to be his girlfriend. I was a boy to climax and just kinda stuterred out a yes and was then in a relationship. I wasn't suppose to happen nor did I realise it at first. I however am still very much in love with my ex and would love to be with her again as I was very happy with her and love her dearly. I am not sure what to do about this situation as I love my husband as well. does anyone have any advice for me on this? it wasn't until recently I realised I was still in love with her. I didn't realise this until I noticed she is the first person I go to any time I am struggling or my depression hits.