Husband stepping out of his comfort zone

My husband is a prostate cancer survivor and he's only in his early/mid 20's. It left him with no control over his bowels or bladder so he wears diapers. Even after being cleared for sex he's still too embarrassed to have sex with me. I tried building his self esteem by giving him a surprise hand job. He was into it until he accidentally released his bowels and poor thing was so humiliated. Well my brother invited him and me on a couples trips for Christmas. It was their Christmas gift to us and he begged my husband and I tried to say no because I know my husband was uncomfortable but my husband ended up caving and saying yes. Well now he's panicking and I said we don't have to go but he said we should and he feels like he's been a bad husband because he doesn't go out with me anymore or please me. I told him that's not true but he said we are gonna go and he wants me to have fun. I can tell he's freaking out a lot. I don't want just me to have fun. I want us both to. How can I make my man more comfortable after stepping out of his comfort zone for me

@Seionaid thank you so much! I never thought of that. How can I bring that up without embarrassing him more?