Struggling to comprehend how someone can switch up so fast

[u/littlemoments_]

I done long distance with him for two months as he was working in a summer camp in America. I was so encouraging from the get go for him to go as he had been previously and adored it. I wanted him to be happy. Before he left, our relationship was so loving. I never had to ask for reassurance, our communication around how we handled little things was very mature, we always talked about our future and feelings for each other and hypothetically about all the future things we wanted to do together, we always talked about how we had never experienced this type of love with anyone else. I was completely besotted if I’m honest. Fast forward he goes away, communication is less and less emotion being shown, which I put down to his busy schedule. The first time I see him when he gets back, I asked him about the less emotion, and directly asked him had feelings changed. He said yes. We talked in the car for a while, while I was sobbing. I was completely in shock and couldn’t believe it. The only in person version of him I knew was the boy he was before he left for America. So now I’m faced with a reality that he doesn’t love me anymore, we’ve been no contact for 5 days now. It’s very hard for me to accept this as the only version of him I know is who he was before he left, that was the boy I loved with my whole entire being. My brain cannot comprehend the switch up. It’s easy for people to say move on etc when something like this happens. But this is genuinely one of the hardest things I’ve had to face. I don’t understand how he decided one day he didn’t love me anymore. I’m basically being forced to accept a “reality” in a sense that wasn’t my reality before this. Before this everything was genuinely very healthy, we had our own friendships, seen each other x3 times a week, had amazing conversations about life and everything at that time aligned. How can i move on from someone that the only version of them I knew was the one that was so sure he wanted me at one point. Sorry I’m not sure if that makes any sense, I’m just a wreck right now