Am i selfish for getting hurt?

I know for the others they will say that it's normal to get hurt, to feel pain, to be sad but for me I don't know why I'm mad at myself for feeling the pain. It should really be normal because you can't control your feelings but I feel bad sometimes because of getting hurt from the things that makes the other people happy or okay. Like this... i have a two bestfriends, a girl and a boy. they got into an argument and now they're finally okay. I should be happy and I want to be happy for the both of them because i love them both and as their bestfriend, I should be glad that they're now okay. but there's this pain that i felt because after that thay're already okay, they have seem to forgotten about me. I have been always there for the both of them but why is it that when everything's okay with their lives, i have no place in their world nor heart? like they only need me when their world is ruined and they have no choice.