I apologize in advance if I seem to have taken your post more personally than would be normal. Your message struck an issue with me that always causes anger and frustration when I see it happening, especially among adults.

I agree with sfalexi's message, especially in that you shouldn't feel the need to "measure yourself up" to your partner's friends and standards. If he can't accept you for being who you are, you need to find someone who will. I would suggest that you simply be honest with him.

I'm also fairly concerned that you're at least partially content to live with the harassment you receive, which you have absolutely no requirement to tolerate. No one has the right to degrade you through insulting actions and cruel behavior, no matter what the circumstances; I certainly wouldn't stand for it, and I sincerely believe that you shouldn't feel obligated to continue enduring those behaviors. The fact that they're being expressed in a derogatory fashion in the first place is juvenile.

Your concerns about future women judging him based on the fact that he's dated you and that he'll be ashamed to be seen associating with you are valid, though I believe they're unfounded. In the same way that men and women have no right to degrade you for being who you are, they have no right (and most would have no desire) to judge him on his past relationships.

I don't know how comfortable you are towards your partner, but I believe it might help to talk with him about this type of thing. Explain to him (or someone you feel comfortable with) how you feel and why you feel that way. If he's able to understand your situation, the extra support may be helpful to both of you. At the least, it would foster an extra degree of trust.

Either way, I feel it's important to suggest that you speak to someone about this. It may help to alleviate some of the stress you could be feeling as a result of your past experiences. If that's not possible, would writing down everything you feel towards this subject be helpful, if you were to read it back once you had finished? It might be something worth trying. Failing all of that, punching bags can work wonders.

Best of luck with your partner, let us know how it turns out.