My partner of about a year and a half (51m) just admitted to me that he feels “guilty” being with me (30f)

backstory: my partner and I met because he was friends with my dad and my brother. my brother died about a year and a half after I lost my father. partner reached out to me after my brothers passing, because he knew I had lost everyone. I had no more family and he was worried about me, because he had lost someone not long ago too. he is the only one who even stuck around at all and has kept their eye on me to make sure I’m okay. and I am so thankful for him being there. And he is so thankful for me being there for him while he navigates grief too. the age difference is no difference to me, but he feels questionable about it. we’ve been having a tough time lately, and our bedroom started to fall to pieces. Last night, I initiated intimacy, just plain hand holding or head rubbing, and he was 100% unresponsive to it. after I asked him why he rejected me, since our sex life was on fire and it just has dwindled to all but none lately. he admitted that he feels guilt because he was friends with my dad and brother. He cares about me and loves me, but that was the conflict he was having. He feels like he is doing something wrong.

I took that as, he felt obligated to be there for me and that is why we’ve been together, and he cares about me and doesn’t want to hurt me but he doesn’t want to be with me. He says it isn’t me, it isn’t anything I’ve done. He’s just felt like this the whole time and he has been able to stomach it until now.

I feel so bad. I feel so stupid. I feel so betrayed. I feel so insignificant. And I feel so confused. I don’t know if I misunderstood him. I don’t know exactly how or why being with me because he was friends with my dead family members would cause guilt. I can’t comprehend what even the fuck that means, and how he could even say that? Not even so much say it, but why would he build a relationship with me if he felt that way?

Basically I don’t know what the fuck to do now and I need advice.