While i dont think you are over reacting, i disagree with vbbeeyoko.

No one should have to think - do i love him enough to loose weight. He should love you enough for who you are.

I would say to him nicely but seriously - there is nothing wrong with my weight. In fact i weigh the same as when we met. You are making it sound like i m not good as i am and i d like you to stop that. If there is anything else going on that i should know about pleade tell me. Otherwise dont ever mention my weigh again.

Wait and see what he says and reasses.

A word of caution! be careful and pay attention to other signs of abusive personality. Trust your gut.