My advice-tell him to come on here and talk.
Written from your perspective-my advice would be the same as above. Read the love languages book.
Couples therapy will go nowhere until individual issues are addressed.
Sex-Maca is a physical touch person. Without it he can't function in a relationship.
GG is a quality time. Without it he can't function.
I am a quality time person.
But-that doesnt make it reasonable for me to tell Maca to "deal" with the fact that I dont need physical touch as much as he does to feel love.
Loving him means making the effort to show him love as he needs it.
Likewise-he needs to show his love for me as I need it etc.
Maca too felt he would be more ok with poly if he found a gf. After 2 yrs of drama-infused explosions he accepted that he isnt ready for another relationship. He started focusing on self improvement and making our relationship great. Which, has led to him being more attractive and desirable to healthy, whole women instead of other dysfunctional women trying to fill a gap in their pain filled lives.
But-part of what allowed him to make those steps, was my willingness to support, love and reassure him ad nauseum as he took those steps.
"Love As Thou Wilt"