Getting husband on the same script

Hi all so we were due to baby dance last night as it was one of the trying days but husband totally shut down and said he just wasn’t in the mood! He knows these days are important but still gets very defensive about trying when kinda forced into it. Hes sees it as a duty rather than fun! This is the 4 th month of trying and we took the pressure off last month by not trying but that didn’t seem to help his sex drive either! Any tips appreciated as I’m at a loss!