Donna, if your friend had "screaming" back pain, trust me, they wouldn't be running a marathon. They SAY they have screaming back pain but I sure don't think they do. YOU know what real pain is all about and there is no way you could run a marathon. If they had your type of pain, they would totally understand, too. I think you might have some "creative thinkers" in your group of friends.
I lost a friend of 32 years last year over fibromyalgia. That's alright with me, too. I don't owe anyone an explanation as to how I want and NEED to live my life. I do what I have to do and then set the rest aside until I can get to it. We just have to make quality decisions in our lives. Look at the things you know you need to do and get them done...like helping your children participate in activities. That is a biggie! Finishing your course is another biggie. The rest will be there when you can get around to it. Your children are probably old enough to be quite capable of running a vacuum and dusting and helping set the table and cleaning up the dinner dishes. You don't have to be an adult to do that. You are giving of yourself to get them to their activities so they can give you a helping hand.
I hope this helps and I hope that your flare ends soon.