Boyfriend leaving for basic training? and AIT?

I've been with my boyfriend for 3 years, and we have an almost two year old daughter. His dream has always been to be in air traffic control, and he wants to leave for boot camp in August or September, so I'd barely speak to him for 2 months. Then he comes home for a week, then he's off to AIT training for 15 weeks where we can communicate some weekends. We have never been apart, we've talked everyday since we met and lived together for a year and a half. He is my rock, I talk to him about everything. I can't imagine being away from him that long. I'm putting on a brave face for him because this is what our family needs, and what he wants, but I'm terrified of how much I'll miss him. Not to mention all the stories I hear about men cheating on their girlfriends... he was watching porn behind my back when he knew my dislike for it about a year ago, and when I caught him he hasn't since. I know porn isn't the same as another person, but I'm afraid of him cheating on me. I have always had distrust with everyone since I was young.... advice on making it through? 😅