I have intimacy issues! Help?

Victoria
I'm 18 and in university and I've been with my boyfriend for almost 2 years, known him for 4. We're long distance now but still stronger than ever. we've never had sex (we are both virgins) and he completely respects that but we both really want to, the problem is whenever we get close, I freak out. I have crazy intimacy issues from my ex and I have a hard time putting all my intimacy into my boyfriend even though I love him so much and we want to be together forever (I know I know I'm young but we have such a big history and we have a very healthy and amazing relationship, he's my best friend.) so I really wanna have sex with him SO BAD just cause I love him so much and I feel so close with him and I wanna feel closer but I'm also terrified of that closeness and of getting my heart broken again. I don't want this to ruin my sex life and make me never want to have sex ever so how do I overcome this? It's totally not an issue with him it's completely an intimacy issue and it's driving me crazy!