I Donated Blood And About 90 Minutes Later I Became

I donated blood and about 90 minutes later I became extremely weak. I went to the bathroom and had diarrhea and then I collapsed in the bathroom. My husband helped me up and brought me to the couch but then I threw up. I was so sick! I went to bed and rested for about an hour but still felt very tired and weak.
Do you think my blood pressure dropped too much after giving the blood?