Should I be upset that fiancé is sexually attracted to only dark haired girls???

So I’m a blonde hair girl and not skinny. Not too long ago I found out my fiancé is only sexually attracted to very skinny girls and girls with dark hair and dark skin. He’s now constantly saying a dark haired girl is hot if he sees a girl on tv. I’m feeling very hurt and feel like he doesn’t find me no longer sexually attracted. I had his daughter 6 months ago. I’m 30 pounds overweight. And feel very ugly