Help! My husband and I....

My husband and I have been TTC but this month he’s just not into it as much as he’s struggling to get hard or cum inside me. I don’t know if it’s the pressure of TTC but I try to make it as natural as possible in the sense that it’s love making but he gets flaccid before putting it inside me and if he’s inside me he struggles to cum. This has never happened before. Any advice? I’m desperate trying to keep his spirits up and at the same time wanting to get pregnant!