Well when people tell me they love me, I have no reaction either or am uncomfortable and want to leave unless I love them too. It would not occur to me to tell them I love them unless I actually love them. So I think the issue is not as much what to do with other people's feeling but more what do you yourself feel for people and what are you capable of feeling. I’d not worry as much how to respond to other people.

Explaining what caring for other people is difficult. We can start with family? Do you care for well being of anyone in your family? Mother? Sister? Brother? Cousin? Grandma? Is their safety and health important for you in some ways? It’s not that different with romantic partner. Excitement and butterflies in your stomach only last that long.. After that is no different than caring for your family

So I’d start with that.