Advice??

Okay so my new boyfriend (who use to be just a fling) is very insecure. He claims I have (excuse my language) but hoes lol. I constantly reassure him that I don't all the time but when I was single I'm not gonna lie a lot of guys tried to get my attention. However since I've been with him I haven't spoken to anyone. He just thinks that someone's going to steal me from him. Not to mention we live 3 hours from each other, I'm in college, he's active duty & im national guard.. Geez what do I do to prove to him I just want his attention?