I Feel as if an Old Friend is Pushing me out of her life

[weathergirlori]

I am a 50 year old woman, married with two children. I have been friends with a lovely woman a few years older than I. We have been friends for about 15 years. About two years ago I developed a treatable cancer, and had my friend supporting me throughout. Although, over the past 12 months, she has been acting weird towards me. She won't answer my calls, or reply to my texts for days at a time. Even on time sensitive issues, i get a delayed response, however, when we are together and she receives a call or message, she responds at once. She has been there for me through illness, and deaths, and happy occasions, and I believe I have been there for her for the same. This is a second marriage for both her and her husband. It is rocky at times, and socializing with them can be challenging as she can be very hostile and snippy towards him. About a year ago is when I noticed the change, she has become friendly with a man that I find very objectionable, and a loud mouth bore. On one occasion, I mentioned to her my feelings about him ( I had known him well before they knew each other), and she said she found him interesting. Recently, we planned to travel together for a two week tour in Europe. I spoke with my Husband, and we agreed I should do this trip, when I tried to contact her about travel arrangements, she told me she had already booked her flight, without even consulting me about it.. I thought it was very odd. I don't want to think the worst of this person, she is a genuine good soul, that will give her right arm for others, but I feel as if she is holding me a arms length, and I can't figure out why. Any thoughts would be appreciated.