@peteronfireee IMO it sounds like something or someone has struck some Fi nerve for you ( as these forms of strongly relating to other people are all Fi-based imo and everyone uses some version of Fi). If this is indeed the case, you will need to give it some explanation to resolve the issue. It could be that you need an explanation as to why you (maybe you were too young? etc) feel you missed a chance or ....i dunno if that's actually the case, but if you attribute even like a very simple explanation to it it will feel better and maybe you will move on.

It might also be that you need to feel it out, so to speak, and then move on (like maybe you didn't realize how attached you felt to this person at the time and now it might be suddenly hitting you?). / 0.2 cents

(PS: yes, they might be dual, you are best placed to know this person's type since you knew them personally.)

ETA: It happens to me to sometimes that if my Fi gets activated my mind goes to unresolved FI concerns.