scared my bf is losing interest in me

I have this fear that my bf is losing interest in me. We’ve been together for three months and, as far as I can tell, things are going great. We met in college and now we have to do a long distance relationship over the summer, although we both have been the 4 hour drive to see each other each week we’ve been home so far. It just seems like lately he hasn’t been as talkative or interested in talking to me - and it might just be me but maybe idk. He used to say “I miss you” and call me “baby” and stuff and lately he hasn’t. I last night “we should facetime tomorrow!” before I went to sleep and I awoke to a snap saying “I work afternoons so maybe” with a black screen and I was like.... ouch. He does work a lot so maybe he’s just tired idk. I just internalize everything and I keep running back through my time with him and wonder what I did wrong. I know it’s wrong to think that way but I’ve been insecure my whole life and idk how to fix it. I’ve given everything to this guy and I like him a LOT. I just can’t tell if he feels the same toward me and it hurts when he doesn’t try to show it like he did in the beginning.

If you read all that, thank you. Please leave some advice down below if you have any.