You have every right to "close shop" - unless it's an absolute emergency, you should not reply to phone messages, emails, texts, etc.
Once you feel a sense of balance again, I strongly urge you to speak with your professors (if you haven't already) to inform them of your situation, mainly for the fact that it may come up again during the school year.
It's okay to need time to yourself - for me, it's absolutely necessary to my continued well being.
If my friends have a problem with me not immediately returning their phone calls, emails, whatever, it's THEIR problem, not mine.
Besides, if they're truly my friends, I shouldn't have to explain myself to them just to soothe their hurt egos.