boyfriend needs space, i need reassurance

He's 22, I'm 21. We've been dating for over 2 years. Up until about 2 months ago our relationship was very satisfactory. He's trustworthy, reliable, loving... the whole deal. However he started backing off from me and (very long story short) is now completely emotionally unavailable. He's been extremely cold to me and has no time for me whatsoever. He called me last week to tell me he needed space for an undetermined amount of time.

He's been going through a very rough time in school, he's doing very well and is very involved in extracurricular activities (he's applying to med school next year). He's one of those people that needs routine in his life, and for the past few months he's pretty much been going through hell. We still live at home so I'm close with his family, and a few weeks ago his mother came up to me and could sense that I was struggling and reassured me that I wasn't the cause of his problems, and that he has been this way with everyone in his family. She told me to stick it through and that once the semester is over everything will go back to normal. Anyways, when he called me last week he told me that he doesnt know what's going on with him, and that if he's not happy with his life right now, how can he expect himself to make someone else happy. He doesn't want to break up with me and that if were to stay together right now he's afraid one of us will snap and end things. He needs time to get back to his routine and to get his life back in order.

As the girlfriend, what do I do? It's weird not being able to talk to him every day. At first I was doing really well because I knew it was what was best for us, but now I'm just getting frustrated and anxious. We spoke for the first time very briefly yesterday by texting, and it was very positive but I could sense he was not ready. We have a lot of mutual friends and some of them offered to "knock some sense into him". But I'd rather have him reach out to me on his own terms.

Anyways, I think I've made this post long enough. Has anyone been in this situation? Perhaps you can shed some light, I'm a complete wreck.

EDIT: punctuation

TL;DR Boyfriend is emotionally unavailable and needs a break, I don't know how to handle the situation