Growing up...growing apart

I never thought I would be in a situation where a friend and I break up...until recently.
One of my longest friendship is, painstakingly, coming to a bitter end.  OK, that's a bit dramatic but it really does hurt something fierce.  It feels like I got dumped...which is a horrific feeling.  Rejection is brutal, especially coming from someone who was the closest person in your life for a decade.
I noticed my friend was growing more and more distant over the past few weeks, months, perhaps years.  I, too, am a changed person and was not consciously distancing myself but it appears I wasn't exactly moving towards a stronger, more connected friendship either.  We met in the eight grade; we were kids then.  We became "best friends" in the ninth grade.  We purposely took the same classes in high school so we'd be in them together.  We went to the same college and skipped the same classes.  We bought the same brands of  shoes/jeans/clothing, etc. We learned how to drive and got cars the same year.  We were inseparable.  We were like sisters.  She met a guy.  I moved to the Midwest.  She visited me twice.  She moved to Florida then back to Massachusetts.  I never visited her in the four or so years she was in Florida.  Phone calls were less and less often made.  Texts started to decrease as well.  We'd Facebook message each other here and there and send Christmas and birthday cards. We just...grew apart. It was obvious we weren't the same best friends we once were but I guess holding onto what we had was worth the strain to me.
Then I asked her if she was purposely pushing away and she said yes.  I think bitterness, resentment, and the fact that we're totally different people who lives so far apart caused a rift.  It's only been a week or so but I am at a loss.  I guess you must let go sometime.
I'm sure we'll reconnect in time.