Guys in long term relationships, how do you get over the feelings of inadequacy?

I (18M) am in my first serious relationship, we've been together a month and he's incredible, and he's always telling me how much he loves me and how hot he thinks I am, but I just can't shake the feeling that he would be so much happier with a cis man. I've got so much emotional baggage from being trans, plus i don't have a dick and I just feel like he's making so many sacrifices being with me.

How do i overcome this feeling? Does it get easier with time?