Partner no longer wants to throw down 😩- Help

My partner and I used to have the most incredible sex life, it was out the gate and I felt so connected to him but for the past 8 months it’s been less and less and is seriously effecting my self esteem and is causing a lot of upset/ often brings me to tears because I feel undesired even though he’s explained that it’s nothing to do with me (still finds me very attractive and loves me). I’m a very sexual person and I’ve left a relationship before (of 7 years) because we weren’t sexually compatible/ I no longer felt wanted.

With this man he’s the love of my life and I’m currently 5 months pregnant with our first baby. I’ve explained how I’ve been feeling and how it’s effecting my mental health because I can’t understand when it was so amazing and our relationship is incredible In all other aspects.

He’s explained many times that it’s to do with how he feels about himself (feels gross in his body and out of control in his work life). I know that this is the case that he’s feeling very anxious and not good in himself and that it isn’t me but I’m at the point m where I don’t know what to do anymore because he’s not doing anything to help himself.

He’s told me he would like to talk to a therapist and I’m so relieved that he’s wanting to do that but has anyone been in this position before where it has helped either them or their partner?

I’ve also suggested couples therapy because Im concerned I might be contributing to how he’s feeling by adding extra pressure. (Needing the intimacy to feel close/ wanted especially with my body changing) but he just wants to go on his own because he’s adamant that it’s nothing I’m doing/ is still very attracted to me and loves me very much.

Sorry for the long post, any advice much appreciated 💗