Seasons of Friendship

I've been thinking a lot lately about a poem regarding people coming into your life for a reason, season, forever, or in and out throughout time.
I have a very long term friendship that seems to be sadly fading into the past. I'm really not sure why.  True, our lives are very different now - different goals, experiences, interests.  But to me that enhances the friendship.  The longevity and loyalty builds an ability to accept, support and understand. I don't believe that relationships are always 50/50.  Sometimes one has to work harder or be the stronger support.  I think this applies to any relationship.  I've worked very hard on this relationship.  I don't mind that, but I've reached a point where it's enough for now. So now I am evaluating what this relationship is adding to my life. Sometimes my husband will be in the room while I'm talking to this person and afterwards he'll comment on how on-sided the conversation was - my part was "uh huh, uh huh, oh really".  He's not being mean, he just cares about me.  And maybe stepping back will allow me the space to make new friends or become a better friend to others.
I also know that no matter how busy we are we make time for what or who is important to us. 
So for now, I've decided to take a break and just see where it goes.