MRI Nightmare

Recovering well from having the PVNS removed from my knee in December. Now Im just trying to get set up for radiation therapy. There have been so many bumps in this process that Im beginning to rethink is it worth it. MRI attempt #1 failed because the nurse didn't chart that I didn't need a contrast prep (to overt allergic reaction). MRI #2 successful and lasted an hour. Well that was to much to hope for. I got a call after I returned home and they said that they scanned the wrong knee. What? It's very obvious what knee needs to be scanned. MRI#3 I took my contrast prep at 7:00 last night woke up at 1:00 with severe headache, spinning, sweating, shaking by 2:00 I couldn't stop puking. By 3:30 my heart rate was so high and I was really scared to the point of almost calling an ambulance. I'm a medic and don't overreact about anything, but I also won't call unless I'm positive that I'm going to die if I don't. Foolish maybe but ERs have their own dangers. I think I reacted terribly to the prednisone since I am now starting to stabilize and it's now 9 a.m. 3rd attempt at MRI unsuccessful. Oh, I forgot to tell you that when I was getting the MRI my knee was heating up I think because it was touching the top of the machine. It was moderate discomfort and along my incision it was all red but not so bad this morning. WTF. I'm not doing anything else until I get some answers. Sorry for such a long post but I think that it's an important reminder that even the most benign tests and procedures have risks.