Feelings are the worst in Boredoms

It's been many years since I've really had a relationship I felt strongly enough about that its loss truly hurts. I've known this person almost 10 years and we've had some great memories in the time we shared together, both as friends and the times when we were more than that. Then a few months ago we have a fight about, really, such an insignificant thing and she stops talking to me altogether. I really loved her. She said more than a few times she loved me, too. Is it really that easy to turn your feelings around?

From what I can tell she's doing pretty well, maybe even better than she has been in a while. It's so selfish but it hurts me so much more to know that. I don't like thinking that I was somehow a poison in her life and now she can be truly happy. Maybe I'm reading too much into the situation...we haven't seen each other since I moved to Washington (about 6 years) so she just didn't really have that much attachment to me anymore, I guess, even if it seemed like she did.

I feel like such a dumb high school kid. I feel like if I don't exist in her world I shouldn't exist at all. I feel crushed and I hate it. Feelings are so worthless.