Stay in control. As hard as it may sound, don't let the harassment get to you. Getting angry or depressed over harassment can be detrimental to your health and studies, and will give the individual or group that is harassing you satisfaction. Though harassment should never be taken lightly, try to work at keeping calm.
Maintain a support system. Surrounding yourself with friends and family that care about you and accept you for the person that you are is a medicine like no other. Don't be scared to discuss what you're experiencing, and take any given advice into consideration. In all likelihood, some of those in your support system have experienced a similar situation.
Seek help on campus. Most college campuses have strict policies regarding harassment in all of its forms. Don't be afraid to report inappropriate behavior to campus administration; they may actually stop the harassment before it escalates. For more urgent matters, contact campus security. College life shouldn't be frightening -- campus staff are there to help you.
Take legal action, if necessary. Some forms of harassment require that charges be laid. Restraining orders can be granted in many cases. Don't be afraid to seek legal counsel if your situation cannot be dealt with otherwise.