My boyfriend of 1 1/2yrs just told me he needed space, for a month :*(.....?

This all started back in january when his ex came back in the picture, saying they were back together and stuff. So, I got really mad and started talking to someone else([not relationship wise but, just someone to talk to because my bf wasnt talking to me]). I eventually told him about it and. I deleted the dude and blkd him on fb because, I saw tha he was just trying to get me and my bf to break up.....My bf stayed the night with me and found the dudes number. Which was fine with me because he knew about it and it was in the past. But, he got upset with me because I had told him that we only talked on fb. But, he gave me his number so that we could talk through emal([yes, you can email a persons cell phone, i.e. phone number@vtxt.com or sumthing.]). My bf got upset because I didn't tell him that part :(. I didnt because I was really scared that he would find out and, breakup with me. Because to him, even just talking to the dude through 3mail, is cheating :(. Now he's saying he needs space. He said he doesn't want to see me for a month. In that length of time, he will forget about me and move on :*(....I don't know what to do. Even though this is June and, I havent talked to that other dude since January. And, I had even forgot I had the paper with his number.....I don't want to lose my bf because we have fought to be with each other. We are trying to have kids and move in together, I don't want to lose him, over something this stupid and that happened in the past. And not forgetting the fact that, he actually went all the way in cheating on me, in the past......:( HELP....I LOVE HIM!!!!!