Losing friends

I've always been a very friendly outgoing person. Looking on the bright side of life. I've been struggling with a disease that has effected my nerves in my leg and stopped me from walking and living my life. 
Recently, it's come back even worse. Its been 5 months now since I've been bed ridden. My best friend is very supportive but, honestly, it's been feeling like she's been slipping away more and more. She's been hanging out with a new girl every day and I know I can't go out and I definitely do not have the mindset of "you can't go out because I can't". I've talked to her about it and she assures me she still loves me more than anybody else but it's really hard to deal with. Especially when her actions don't measure up to her words. 
Anyone have advice? Or even problems they want to share?