Really tough :/
First thing, if you havent already, is to examine all the fine print of your lease. See if there's any early get out clause or anything that could be used that way. Perhaps if you found someone to take over? sublet? Perhaps the penalty is low enough to consider it if you're that unhappy?
Assuming that the penalty is paying to term and/or losing deposits etc. and there's no early get out then things are more sticky.
Investigate state laws on leasing, you may find something useful and it'll be useful to brush up on them before the next stage.
Put together a factual record of problems including their responses. Write a summary cover letter stating exactly what you want the outcome to be. In other words don't go all mushy and ask can they help, say clearly that you want to exit the lease early and that's that.
They may well be more ready to talk about the options than you think! After all, it's better that than have you skip out (and as you already know, that's a non-starter for your credit record anyway).
If your school has an accommodation office which students use to locate apartments, go talk to them and get them on side. No landlord/complex is going to want to be blacklisted by the local school and they may decide it's less risky to let you out and get someone else in than take that chance.
If all that fails and they really won't even consider budging, then consider local zoning regulations such as environmental/noise and so on. An intervention from officials will add weight to your case and again, they won't want you there making trouble for their complex ;-) Again this is one you can use without actually DOING it but be careful to innocently suggest it rather than threaten it... ie. "I'm just at the end of my tether with it all and I'm so unhappy there :( my parents have suggested going to enviromental health because of the health risks but I dont want to cause trouble :( but perhaps I just have no other way" is better than "yeah? you IDIOTS I'm gonna call the cops on you" ;-)
Finally if no go, another letter formally stating that you are no longer willing to continue with the contract because you believe that the place has been misrepresented to you and is a health risk etc. and suggest mediation to come to mutually acceptable terms. Again written in a no-nonsense businesslike way but not confrontational.
End of the day, sadly, it's a legal document and just as it protects you against being thrown out, it protects them against someone just deciding to up and leave. So it's going to be much better to come to a mutually agreeable solution. It seems to me to be the right time of year for them to be able to find a new tenant pretty quickly which should help.