Learn. Don’t just say you’re bad at comforting people. Actually take actions into giving what your partner needs. Do research, practice, anything. Overcome what could possibly be the reason as to why you can’t comfort him in times when he’s down (not saying that there is one, but could be). Meet him in the middle is basically what I’m saying. Everyone needs someone to comfort them at some point.
I think the best thing you can do is set a boundary, since this is something that makes you uncomfortable. maybe offer to just listen to him and see how you can help him in other ways, but make it clear that you don't have the means necessary to comfort him. ask him to see if he knows any of his friends that he can try to find emotional support/comfort from
I also suck at comforting and we had to work out a compromise. Im bad at words, but my ex found hugs and physical affection just as comforting. I also had to train myself to ask gentle questions so they felt supported, and *eventually* I would parrot back language they used on me that I found comforting
I’m not saying I don’t try. I’m saying he doesn’t like my attempts. I think it’s the sincerity that’s the problem. I have a hard time portraying sincerity if I don’t believe what I’m saying. I can’t just say things I don’t mean. So when I try, it sounds awkward and fake. “It’s going to be okay.” Isn’t something I know to be true all the time. Other times I believe him to be in the wrong when he’s upset about stuff so “You’re right.” sounds off. He’s even told me he doesn’t believe me.