BD Failure

We entered our fertile window yesterday so we started to BD. My husband has been recently put on Zoloft for OCD and anxiety. Last month was hard b/c he couldn't finish due to the medication. Last night he couldn't stay hard. So I think we're out already for the this month. He wanted to stop his medication for a few days but I know that's really bad for him to do. So I told him we'll try again next month after his medication been in his system for a while and his body adjusted to it. I pray next month will be our month!!!