Seasonal Friendships

I have always believed there are different levels of friendship and most friendships are seasonal.  It seems most people enter your life when you need them the most, but they don't stay for eternity.

I have always been okay with this idea, not finding anything wrong with the fact that people fall out of touch and through no one's fault in particular, they aren't as close as they once were.

What do you do when you don't want the relationship to be seasonal?

My heart is breaking as I realize my relationship with a friend of mine was seasonal when I thought it would be for eternity.  This friend was more like a sister than a friend, and if I have to be honest, I feel like my heart has been ripped out.

Perhaps I was foolish for thinking our relationship was more than seasonal?
Perhaps I am just being immature?
Perhaps this has nothing to do with me?

All I know is there are no more outgoing phone calls, no more returned phone calls, and no more girl talk over dinner.

I keep waiting, hoping this person and I are just going through some growing pains, that perhaps we will recover, that she will tell me if I have done something to offend her.  (I asked...)  So far, nothing.

And perhaps this is just how it was meant to end.
Seasonally.
It sure doesn't make it hurt any less....