Me(F20) and my boyfriend(M20) of 2 years are high school sweethearts. Turns out he’s been sorta cheating? I don’t know where to go from here!

Hi Redditers. I’m in a bit of a situation. Me(F20) and my boyfriend(M20) of 2 years are high school sweethearts. He is in the military and lives 20 hours away. We maybe see each other once every 4-5 months. I’ve known this man since we were 6 years old and been with him through everything from his parents divorce to boot camp. We’ve been going really strong for the past year or so (very)long distance. This weekend he came home for a concert with my brother and his fiancé. As I was getting ready to go and using his phone as a mirror a girls name popped up with the text “hi baby”. I wasn’t sure if my eyes deceived me so I looked again and sure enough. I didn’t press too hard about it bc my brother was nearby. I said that we would talk about it later. The next morning I woke up before him and went through JUST his texts with her. It was incriminating. She is also in the military(same branch) and says that they have been talking since he got home 2 months ago. He swears on my life that nothing physical ever came of it and I can’t find anything to prove that wrong. I woke him up and brought him to the airport immediately where we proceeded to argue and cry for the next 2 hours in the terminal. He has been back home for 12 hours now and still hasn’t tried reaching out to me, even though he was begging for my forgiveness at the airport? I’m just confused and concerned at this point. I really do love him and ik we are young but knowing him my entire life makes it feel like forever. I don’t know what to do know bc he still hasn’t answered my texts. Please help a girl out