I was addicted to drugs

A guy offered to have a friends with benefits situation where if I helped him out, he’d help me out. We would fuck all over his house; in his garage, backyard, hotels, car, everywhere. It was great sex at first because he was so intent on pleasing me in every way possible. Turns out he was married with 4 kids and another on the way- which I knew at the time, but didn’t care about because of how addicted to drugs I was (which he could easily attain and gave to me for free). He talked me into having a threesome. His wife found out and hates me (I’m not even sure if their still together). I have no excuse for my behavior. I quit doing drugs cold turkey and stopped all contact with him and all the poisonous people in my life over 2 years ago, but I think about my actions everyday. I’m sure no one gives a shit but, I’m crazy in love with my current boyfriend. I only slept with the both of them for the first month of us “talking” because we weren’t serious or even dating, so I’m not sure if that means I cheated… Probably does, right? My bf and I have supported each other through all our tough times and he’s my best friend. However if he found out I would lose him. I’d rather hate myself for the rest of my life than be without the best man I have ever met.