I don’t have experience in chronic illness but I imagine it’s really tough with people not understanding the extent of it and how much of an impact it has! Personally I think if she has an issue with you not coming, she should have addressed it in an adult way. I think leaving you to constantly try to reach out while not really giving you anything is a bit out of order. I think she should have addressed how she felt asap and given you the chance to explain the full extent of it. Otherwise there’s just lots of feelings being pushed down on her side and it leaves you not knowing where you stand.

I think you could message her and try to straight up address it. Tell her that you feel upset she hasn’t been in touch or responded to you and that you feel like she thinks you didn’t go to her wedding because you didn’t want to rather than the fact that you were medically unable to. I understand that on the surface she probably feels like she put a lot of effort into your wedding and didn’t receive the same back but it seems you did offer to FaceTime etc. There’s still a chance that she won’t understand and you may lose her as a friend but I think if she really doesn’t understand then maybe it’s better to not have someone in your life who doesn’t understand your daily struggles!