Ttc is ruining my marriage.

I had a baby at the age of 17. Now I am 33 and married. My husband doesn't have any kids and the only thing he wants in this life is to be a dad. And for some reason, I can't get pregnant. We have been trying for a year now. I've seen my OB and he put me on clomid for 6 months but now wants us to see fertility docotor. But, I already know one problem. My husband has trouble "finishing" during bd time. He says all he thinks about is having a baby and can't focus anymore. He was tested, and has a very healthy sperm count. But bd time is so frustrating that neither one of us wants to even do it. I tried to talk to him about him not being able to finish last night and he just got angry. I don't know what to do any more. We have almost been married a year and should be having amazing sex. Instead, we dread it. I get more depressed every month I'm not pregnant and not sure how to fix it. Thanks for reading, I needed to vent to someone.