I was discharged about fifteen minutes into donating plasma and platelets because my arm started to form a hard bubble during the process. I have had a rather large bruise on my arm ever since, but not really painful. Then today, nine days later, my arm began hurting really badly and I am having a cold sensation in the area the needle was inserted into. It hurts to apply pressure to the area and is just very painful all around. Any ideas what could be wrong and how to alleviate it? Thanks!