How to deal with uncertainty in a relationship?

This really hits home with me unfortunately... My boyfriend and I tried long distance relationship without really knowing when we would see each other next. At first, it was ok ya know, we'd text all the time and talk on the phone. But eventually things started getting to us. I trusted him and he trusted me, we would go out with our friends and such without the other freaking out( this part was hard for me cause I too am a control freak and I know how his friends are) The point, we broke up today cause he had sex with this girl who he reassured "there was nothing there". I think the percentage of LDR that work out are worse than marriages that actually work out. Sorry and beat of luck to you.