An angle I haven't seen addressed so far is that unless you stand up for yourself, it's safe to say the situation there will never improve. You will always be a target for them.
There's already been lots of good advice on the legal/moving/etc. options, but I'd suggest you also consider giving sh*t right back to your tormenters. I don't mean doing what they do (harassment), or stooping to their level, but giving them some "good-natured" ribbing right back at them. This tends to disarm "good ol' boy" tormenters, and even can win them over to liking you. Example: They say you must be blowing the boss under the desk, you tell them they must have been watching. They say you're gay, you say "Yup I sure am gay and happy today, you definitely look GAY and happy too." Say it with confidence and a smile, like you're joking with an old friend.
It might seem crazy, but bullies like yours warm up quickly to guys that give them some good-natured but firm ribbing back. If you don't give it back at them, they figure you're not one of them, and you're weak (and therefore should be tormented some more). There are lots of examples out there -- city vs. country folk, officers and enlisted, blue collar and white collar -- the outsiders will be treated with contempt until the mainstream group sees them doing some of the same things they do.
I once had a situation where I entered a job as an outsider. The profession was very much a "tough guy" one, with lots of danger and bravado and locker room talk/antics. Then comes me: a white collar guy of medium build/height entering a job full of badass, tough blue collar types, and I was treated as an outsider. They only dealt with me in the minimum way required, completely shutting me out of anything else. One day the guys were joking around and swearing with each other, as usual (not including me). One guy who was about 6'3 and 300 lbs. was telling the others some story about how he messed up something he was working on with his car over the weekend. Out of nowhere I looked at him (all 160 lbs. of me) and said, "You must be some stupid fucking asshole." He looked at me for a second in disbelief, then bust out laughing along with the others. After that I was included -- I was "one of the guys" and ended up being good friends with quite a few of them. I realize your situation is different, but the same principle can apply.
Disclaimer: I am not in any way condoning what your tormenters are doing, or suggesting you should end up being friends with them. It's f*ed up. I'm merely pointing out the reality that they will continue to treat you like an outsider unless you stand up to them with some more "kidding around" back at them.