Hubby help

We’re trying for baby #2 for like 4 months now. My husband has been having a little bit of a problem having sex more than 2 days in a row. I’m trying to do day before O, day of, and day after and we can never manage it. What can we do? By the third day he can’t get it up. We never had a problem before. His drive is usually so much higher than mine and now it’s almost gone. Help!!!