Is what I did cheating? I feel like a POS

Before this starts we are all adults I'm 21, my ex is 20 and my bf is 25. Just clarifying so people don't think I'm in HS. So recently my ex added me on Snapchat because apparently some girl I used to be friends gave him my Snapchat username and he has been trying to add me back for 2 years after me denying him, I made a new account and he added me again so I finally just asked him what he wanted since he kept trying to add me. He apologized for how he had treated me in the past and how he just wanted to be friends. I told my boyfriend about it and said it was good I was giving him closure. Well I told my bf I wasn't talking to him anymore which I wasn't that much because if anything it was like up to 3 messages a day and most of the time I would open them and not reply even though technically I was still talking to him. my ex has made it clear he wants to get back together with me even though he first said he just wanted to be friends, when I've told him I'm in a relationship countless times. I ended it and removed him from Snapchat. I even had a dream that I cheated on my bf and I ended up telling my boyfriend what happened and he was mad that I lied because I said I wasn't talking to him anymore. I have apologized a lot and feel really bad. I don't want him to feel like he can't trust me. Did I cheat? Nothing that was said to my ex was flirtatious at all and I told him I had a boyfriend a lot of times but I still feel like a cheater. Sorry for the long post.