My two cents, for what it’s worth—
I’m imagining it’s a situation where one person says “I really do care for you/love you/want to be with you,” but the other doesn’t find the words convincing. Is that the idea?
I would take him at his word, to start.
There is clearly a disconnect between what he does/says and what I’m looking for, but it’s not necessarily one that he’s deliberately hiding from me.
Then I’d try to start working to understand what affection and relationship mean for him versus for me. What am I looking for or needing out of a partner that I’m not getting in this relationship? And how, by contrast, does he express his affection for me? (And vice versa).
Once I figure that out, (or even while I figure it out,) I can share it with him and we can work on it together. Maybe there are ways I can better understand him and see where and how he shows his affection for me. Maybe there are specific things I can request of him, and see if he’s open to doing to show affection in ways that are meaningful to me. Etc.
…Maybe my needs can’t be met in this relationship, for whatever reason (but I’d cross that bridge if I get there, not before).