JFC, that's heavy what happened to your partner. I'm not a therapist but tell him that I send him good vibes and wish that he can forgive himself soon.

As a partner, father, and community member I completely get why people stay in sexless marriages (several of my friends are) and why people cheat (some of my friends have).

We're all human, we want connection. We want cuddles, making love, raw sex, and ice cream. I normally don't advocate for divorce but you got one freaking life, make it a happy one. If that includes getting railed till you see rainbows on a regular basis, then make that a big important part of your life. Hell, I know it is for me and my partner.