I think I blew it again

Ugh..it's me again. I think I really screwed up at work tonight. I work in a hospital and we had to give plasma to a patient. It went okay so I thawed another unit to give. The thawed unit didn't appear to have ice chunks and I set it in the fridge like I was supposed to. Four hours later they give the unit and I think another hour or hour and a half after giving that one they call and say it's a transfusion reaction. I'm scared that I screwed up. They did a workup around the time I left and I cried on th e way home.......I really think it's my fault. I'm scared something bad will happen to the patient or I will be fired. I'm trying to think of what I did.
I'm worried I didn't thaw the plasma long enough or that I missed something. There was no problem with the first unit, just the one I gave. I apologize for it being technical (any lab tech's or nurses are welcome to help) but I'm scared that I massively screwed up. I have never had this happen to me before and I have done blood bank for four years....I don't know what I should do. Thanks and sorry for the rant.

Update, I called the next day after I calmed down and they said it wasn't anything I did. The person I talked to understood why I called and said that everything was fine. It was just rotten luck.

your reaction simply shows that you care about doing a good job and that you take responsibility. You should congratulate yourself. So many people today lack those qualities.