Hubby frustrated!! !!

I been TTC for the last 6 months, nothing happened yet so every month we keep trying. I'm in my fertile week but my hubby can't performed, when we do our foreplays he get so hard, as soon he get inside my vgg he got soft. That keep happening this week. This is the first time that happened. I can see how frustrated he is, he's mad at himself. I told him we can try next month for him to take a break. Yesterday he went to the doctor, the doctor said that he's fine, anxiety can do that. I have 2 kids from previous marriage, he got one from previous marriage also, none together yet. He's so down, I can see his getting depressed, that's my fear . Last night he didn't come to bed, he fall asleep in the couch while watching TV, he never does that, I don't know what to do to make him feel better about himself. Any ideas will be appreciated. Thank u!!