hey vilue, to be really direct and candid, perhaps even
offending, by probing him to talk won't make him talk. If he really
does, it could be bad news.
Why not try a different approach? If you're sincere and wishes the
relationship would go on, allow him to figure things out. Far too
often when a problem comes up, we don't even know where it came
from. Give your bf his space, give him comfort, love and support.
He most probably have a lot of other problems including his
studies, family all bundled up together, making him very
confused.
Cliche as it sounds, it's a lot of give and take. If you're there
for him during his troubled times, even if he says nothing, I can
assure you he IS happy that you're there for him. Given enough
time, he'll talk.
Maintaining a loving relationship relies a lot on communication.
And when i mean communication, i mean talking to each other with a
problem solving approach - with a heart to mend the lines; not
bitching and bitching and complaining and lamenting. 
