reserved bf ?!!! help!!!

I never saw a problem with my bf not being really communicative until now it's affecting me.. I wish he would just tell me everything how he feels what goes on with his life but he keeps everything to himself.. we've been together for 1 year and 6 months I still can't seem to help him be more communicative with me.. does anyone has this same problem? If so, what did y'all do to either make it better or cope with it