Why isn’t my TV getting cable?

I have a 15" SHARP flat-screen TV and have recently arrived at college for sophomore year.

Last semester, I got all channels available on campus and perfect picture quality. When I went home, I used the same cable with the TV in my room where the cable has been kind of messed up for a while and got all channels EXCEPT 13 through 24 (it just completely skipped those numbers when I would try to channel surf or type in a number in that range), with decent quality. Now I'm at school and, with the same cable I used at home over the summer and at college last semester, and no only am I getting only white noise, but it still registers as skipping channels 13 through 24.
The instruction manual has not been extremely helpful.

Does anyone know what the problem might be?: The cable, my cable jack in this new dorm, or the TV?
Cable is "free" (ie. included in rooming expenses and I've paid), and though the cable cords themselves are not provided, there's a spot to plug in by the ethernet spots.

Anyone know why at both home and here in my new dorm it would randomly be skipping eleven channels?