Imho, sometimes it's important to feed the soul and accept the payback . Many times, I have lay in bed in agony -- but thinking of how my heart felt better from the energy expenditure that got me there gets me through. I participate with eyes wide open.
And I feel in a better place on levels beyond strictly the physical. ( of course still cursing the pain and this plague ;-)
That said, there are times, when I can't push to do that-- or when I decide that the "price" is not worth the event. That part is very personal and can vary from event to event and depend on where I am symptom wise and also with coping abilities in any given time. Not to mention, what it is that I *need* to do in the days after.
When I accept invitations, I always say I hope to come, but please understand that I may have to cancel last minute.
and I find most friends will supply me with a quiet room and bed or couch to take breaks if I need to. or something to put my legs up on while there, extra cushions to be comfy ( and if at a restaurant, I take my own pillow for my back). Whatever it is that might make it more doable and less payback for me.
Sometimes a time out on that couch or bed really helps.
I have had to learn to really advocate for myself for stuff like that. Never came easy for me in the past. Much better at it after all these years! I have been lucky in that on those rare times I am able to say yes, most friends are happy to make accommodations. (Of course, those who really "get it" or at least have true compassion even if they don't fully understand, are rare gems!)
Going out for such a holiday to be with friends sounds lovely. A luxury. And luxuries have high price tags. If you decide to accept the cost I hope reminding yourself in the days to follow, the joy of being with friends to get you through.
And I hope you are able to feel joy.
(( Carringon ))