You just tell them your condition means that you are limited to what you can and can't do. If they get upset because of it then they aren't much of a friend. Focusing on your own well being is more of a priority than wearing yourself out and causing yourself more pain

I have always been super active and very involved so this has been quite a learning experience! I have explained to my closest friends my limitations. To those with whom I am not close, I have had to practice saying no and not concern myself with their opinion of me. You need to focus on you and give yourself permission to say no! Good luck!

Just practice saying no. Then actually tell someone you can't do something. You don't owe anyone an explanation. It is hard to say no but it gets easier the more you use it. Love yourself enough to get the respect you earn.

Practicing saying no sounds best...thank you, all of you xx

I don't think I would cut everyone out of your life. Explain to them why you often can not go with them. Let them know what you can do and then you can join them. Maybe just one person at a time and not a big group.