I gave plasma for the first time on Monday, I gave again yesterday, by the afternoon I could not move my neck very much, stiff, today it is impossible to even reach down to lower my pants to pee. If I lay still I am OK, but as soon as I go to move it is almost impossible. I have to move my neck and upper shoulders just at the nape as one unit. I did not sleep funny as I was awake and doing homework when it started. I tried applying warm compresses and this relieved it just as long as the heat was there. What could it be?