I too have been working on this. It's very VERY difficult though when those stupid emotions start popping up. It seems as long as I'm somewhat calm I'm able to be at least a little positive lately, which didn't used to be the case, so I'm making progress at least. I'm pretty calm now, so let's try.

A couple positive/grounding thoughts I'm trying to really focus on lately:
1. I'm happy with just friendship (referring to my "favorite person"), it's completely ok if that's the extent of it.
2. It's ok to love a friend and want to cuddle them, love and physical affection is not reserved for mates. (Validating my feelings a little bit there.)
3. If anything more is meant to be, it will be, but now is not the time. Even if it will never be, see #1.

It's sort of a cycle I repeat in my head. It doesn't usually do anything if I'm already upset, but while I'm calm it helps keep me calm.