MEN ARE SCARED TO EXPRESS THEIR EMOTIONS?

i LOVE my bf of 2 yrs, we had a rocky 3 months so far, with breaking up & him looking for me & getting back together. He has an issue with expressing his emotions which I am now better understanding (research, books, etc.), I've wanted him to express it like me, but Men are different & although he doesn't say it, he sure does show it but then he becomes scared & backs away for several days, a week & a half at most, I don't hear or see him. But when he reappears he shows me that i'm the ONE. Unfortunately, this has happened since 3 months ago, & have found that this is typical 4 some men. He feels so much, he is scared to be so vunerable to some1. What are your thoughts & what can I do to let him understand I'm not going anywhere because I've decided he is for me as well. How can I deal with this without it hurting me? Thanks !