51 year female, History of Hyperthyroid disease (Graves disease) ...

51 year female, History of Hyperthyroid disease (Graves disease) treated with radiation in 1984, now have Hypothyroid taking 100MCG Synthroid. Began 20mg of Simvastatin 4 weeks ago. Developed mild rash, hives off and on but that was normal anyway so I didn't think anything of it. In the 3rd week a Co-worker noticed that I was walking a little stiff and thought my foot problem was back but I mentioned my knees felt strange. Again this is normal with the cold weather here. This week my knees and calves were swollen and I could hardly walk down the stairs. I called Urgent care and they told me to stop taking the Simvastatin. It's been two days and I feel better but I wonder if my joints will ever be the same? Will I walk normal again? What's next if I can't take statin's? Red Rice Yeast has been banned.