I need some serious HELP!

My husband and I started TTC about four months ago & it’s been a whirlwind of emotions on my part because obviously every month with a negative definitely messes with my head but recently my husband started losing an erection, DURING sex with me. I don’t know what’s going on. He says it’s just him in his head but he’s been more distant too and I just don’t know anymore. My husband and I have been together for 5 years and our first wedding anniversary is next week. I just need some help and not dig into my own head that it’s me and not something else.

I’m 24 and my husband is almost 26