Xbox live not working after dash update/profile now gone

Hello, bit of a base problem here but hoping somebody knows what's going on or is dealing with something similar.

Long and short of it, after the dashboard update last December(ish) I can't access Xbox live. It's not my profile or console as it works fine at home, so I'm guessing it's NAT settings or the University firewall (Or something of that ilk). This was fine because I just played offline like a rational human being and coped, until I tried to re-download my profile (Because I am full to brim of fantastic ideas) to see if that would alleviate the problem. It did not, my profile is now off my console and floating around in some sort of Purgatory until I get home. So yeah, that's kind of a hindrance, especially as I now can't play any of my games unless I start from scratch, and I'm paying for a service I can't even access.

Hopefully any students or folks from ISS know what's going on. *Obligatory smiley*