I recently had trouble finding the time for NG. Although that problem has now resolved itself, and I technically have plenty of time to myself, ironically enough I find my interest in NG waning slightly. I haven't been statwhoring at all over the last few months, and more often than not I'll only really deposit my experience and leave it at that.
Anyway, I'm trying to regain my love of NG, just by making sure I do a few bits and pieces each day (other than depositing), for instance, commenting on news posts, posting on the BBS, maybe a blam point or two, etc etc. I think the 30 minutes a day thing is a good idea though, I may well try it.
Good luck for your last year of uni!
C-Hawk
I'm currently in that same situation. My only suggestion to you is to make a sort of "shrine" where you can study and nobody can bother you, get some good headphones, and don't care if people think you're an asshole for not helping them. You come first.