If you have serious sick time built up take it. Show up at yer docs and tell him straight out that they are trying to fire you over being sick. You have x amount of sick time built up use it under HR guidelines. Then be brutal with your manager. Tell him you feel the company is taking advantage of you, disclosing HR records to co-workers is illegal and nastily ask if he knows of any lawyers that like to do wrongful dismisal suits. Tell him that you are a loyal employee but feel the need to place your interests over the companies interest due to bad management. Do it in writing and CC the Senior Partners. Before you do that on the QT find out which firms seriously has a grudge against yer firm and if anything happens approach the immediately. I do not advocate suing, just let them know if they let you go it is to their benefit not to fsck you any further. You are competant, knowledgeable and these fsckers are looking for sweatshop workers.
my 2 cents,
bill