He had been texting his girlfriend for a month. They never saw eachother, or did anything physical, it was purely texting. ...but it got to the point were he said he loved her.

Before you guys say "leave him" a little background on us. We've been together for over 2 years. Aand basically.. perfect for eachother. Anyone can tell. We're not lovey-dubbie we just perfectly co-exist in harmony with eachother. We're always together, we laugh, we play fight, we get angry and laugh about it, we workout together, we pig out together, we get along with eachothers friends and families, we can't be apart for more than a day. Friends usually come to us for relationship advice. We were even voted best couple in school. We're strange but for some reason we can't get enough of eachother. He is the person i go to for anything. I've never been as close with a friend or family member as I am with him. He knows me better than anyone in the world.

So when i found out he had this emotional attachment with his ex from about 3 years ago I was in complete shock. I saw the text, he did not tell me. He cried and begged and i took him back quickly. I just knew it was nothing serious besides him being a totally stupid and a complete ***. The worst part is he can't say it was a one time mistake because he had been talking to her for a month. I feel completely betrayed and like the biggest fool. But taking him back was easier than letting him go.
Recently though, I decided the smart thing to do was end it, because although i still love him and we still have tons of fun with eachother i will never be able to forget. He is leaving to the military and ill be leaving to college so I figured might as well let him go now so he can enjoy the rest of his summer without me bringing him down with my mood.

I've never been so sure of anything in my life. I still love him and i want to take him back. I know he loves me but I don't know what i should do.
I desperately need advice... I'd love to hear your guys' opinions. Thank those of you who took the time to read this.. what should i do?