With regards others - saying 'no' gets easier the more we practice! When asked to do anything for someone: I was the 'go to' person for years

: I now tell them that I have to 'consult our calendar in case DH has put something for the same date'. After a while they learnt that actually, that meant a 'no'

'they' have managed without you KaraShannon - so harden your heart. Say 'no' for a few months - make suggestions as to appropriate agencies, charities, other groups that 'will help'. "I suggest that whilst I continue to recover, that you approach X, Y, Z". If 'they' continue nagging at you to problem solve, then 'Which bit of NO don't you get?' That has worked for me thus far ;-).
Put foot down with firm hand. U need to build up your own energy levels, because we are 'out and about in public' doesn't mean that we are 'up and running'. U could also say that 'some private conditions aren't obvious '. It isn't up to others to judge, but they will do until .....