How hard is it to let go?

For the past eight months I have been overcome with sadness after I damaged a growing friendship beyond repair because I liked that person. Would you call it love if you had feelings for person that you hardly new and you believed you did. To me it was so...

I've tried to move on from this love but its not working at all. Am I meant to make myself more busy? Am I meant to seek more people? Am I being selfish? There are so many questions that I am asking and as a result I become clingy.

I have annoyed people, let people down because of this and I'm sorry.