In need of some advice! Please help!

Courtney
My boyfriend and I met online... We have been talking since August. He had to leave around the time we started talking because he got stationed in another state 12 hours away.. We never met before he left but we did FaceTime and snapchat regularly.. I visited him in December at his base where he asked me to be his gf.. One day in Jan he contemplated breaking up because he was stressing about possibly being deployed and wanted the "focus on the deployment" that lasted a day then we were back to talking 24/7.. The distance was too much and I moved in with him on Valentine's Day to make our relationship last because I fell in love with him.. Today 4 months later I found out that day he contemplated breaking up he slept with another girl while we were still dating... Should I break up with him or give him another chance