Been dancing around what to type here.
I think cheating is fucked up. AFAIK, I've never been cheated on, but I would hate it if I was. That being said, @Richardheadhas been cool with me. I hope you get things sorted.
As for online dating. I was hesitant for years, but took the plunge. 4 dates in 4 months. Been with number 4 for over 3 years, and recently got engaged. I thought I was gonna die single, now, I'm living proof that it's possible.