Maybe you are losing your best friend but not permanently. I feel lucky that I have a handful of very close friends who are in all different stages...some single like me, one getting married, another in relationships and one married with 2 kids. Two of my closest friends I went through periods where I felt the friendship was over or close to over only to find it reviving again. I'd say it was a good year or more in both cases where I felt that it was just about over. Today they are still 2 of my closest friends. As a single girl its tough when a friend has children because the spontaneity is gone and it becomes a chore to try and really make plans that stick. I was always asking when I could come over and see my friend and her kids and she always had one obligation after another ALL the time. I told her a couple times it was ridiculous that I had seen her in a year because of her not being able to give me a date. She just recently came around to how important it is for her to make a plan to see me and realizes how much she really missed our time together. I was hurt but chalk it up to maybe one day I will understand when I have kids so feeling hurt works both sides when one friend has kids and the other is single and free. Take heart that your friendship may just be changing and that it is pushing you to also look towards opening your heart to a new friendship as well.