Oh sweetie, **** those jerks! I know it hurts, but remember they are not your friends, just because you work with them doesn't mean you have to put any credence to the things they say.

Also, there is nothing at all wrong with being gay. If you are not too timid, why not ask them how saying you are gay is an insult exactly? Maybe turning their behavior back on them will make them see the jerks they are being.

Are you nervous around women? What makes you feel you are a loser?