Welcome to a family of support for lupus patients. Trust me, many of us if not all are not happy about it either. We have good days, bad days, and better days and try to cheer, listen and have empathy.
You have to accept it and move forward the best you can.
It sounds like you have chronic fatigue syndrome along with Lupus "feeling like you ran a marathon" is typical. Chest pain could be either costchrondritis (sternum pain and sternum is swollen) usually on the right side of your chest.
Pericarditis is on the left side of your chest by your heart. Saysusie can help with this one, but I believe it is when your heart is surrounded with fluid. Low back pain sounds as if you may have fibromyalgia which typically effects Lupus patients.
Most doctors will start one out on Plaquenil. prior to beginning meds, you will need an opthamologists appointment for a baseline Plaquenil scan along with check-ups every 6 months. Plaquenil will help with the joint pain. If you do have fibromyalgia, some doctors will rx Flexeril to relax teh muscles at night so you may get a restfull sleep.
Write a list of all your questions prior to seeing the rhuemy. Also, document all of your symptoms and show the doctor.
Keep us updated. I hope this has helped.