Have you ever donated plasma before?

I donated some the other day. It was really gross and freaked me out. They put the needle in my arm. After they put it in my arm, I watched the blood slowly come out of my arm. They took a lot of blood out of me. After they took out all my blood, the pulled out the plasma and put it back in. That is the worst part. I don't mind them taking the blood out as much as I hate watching the blood going back into my arm. It made me almost pass out. I was very close. Luckily, I was laying down which prevented me from passing out.