It's unfortunately against the terms of use to let anyone else, even a family member use your account.

The only exception being a parent and a minor.

There should be no problems restarting youe sub after a few months away, there are people who've gone away for over a year and returned without an issue. Unless of course you've signed for the annual pass in which case you could have a bit of trouble, that aside though you should be fine.

I'd recommend getting an authenticator for your account if you've not already got one, would suck majorly to come back and find your account compromised and gutted, though you'd likely get it restored, it's better to completely prevent it in the first place =D

Good luck with your studies hope you come back with good news along the lines of passing with flying colours!