I need advice!!!!

My name is Amber, im 21 going to be 22 in 2 months. I lost my virginity 2 years ago to my "high school sweetheart", him and i started dating on and off from 2012-2016, we would go back and forth. I moved to florida in 2013, came back in 2015 then me and him started dating again on and off AGAIN. Well he has a baby mama 🤬 he would date me for 1-2 weeks then go back to her. I should have stopped but i was in love. Well I officially had enough after he took what he wanted and left(like i knew he would). 2017 came along and i met my fiance, we've been together since January 2017. Still going strong. WELL, now i find myself thinking of my ex, everyday. Wanting to talk to him, looking for him when i go back to my home town, stalking him social medias. I feel like im cheating.... i love my fiance more than i ever loved anyone else. My friends think its because i wanted this life i have with my fiance with him... my bestfriend thinks i should talk to my fiance.

Well, ladies what would you do?