Hi Ailsa
Please don't feel bad about being off work! I understand where you are coming from, the worry, guilt, about letting down your Year 11 students; however at this point in time surely they are on revision material anyway and top set students should be able to get their acts together with a supply teacher for guidance. At the end of the day your health is paramount and if you don't get it right now who knows what the future holds ... RA is such an unpredictable disease!
I agree totally with Poppy and Jenni, the chest pains will likely be inflammatory and most likely Costochondritis; inflammation of the cartilage of the ribs, in particular, the cartilage that joins the ribs to the breastbone, at the front of the chest. It is a separate condition but often occurs alongside RA. Neck and shoulders will probably be the RA.
It certainly sounds as though you are going through a flare and a review of the meds would seem necessary. If you don't hear anything today I would follow up with a phone call to rheumatology because you could do with something more to get things under control quickly. Sorry you are feeling so rough and hope you get some relief very soon. BUT please don't be tempted to dash back to work too soon!!
Lyn x