Thank you for your insights! I'm feeling much better today. I've never had that problem when I've donated before, but I was also not dieting in the past when I've done it. I think maybe my blood sugar was already a little low before I donated. I'd had an unusually low cal day the day before, with little protein, low calories early yesterday and had just finished quite a workout before I went. I also remember when I had my glucose test during pregnancy I was told I was a little on the hypoglycemic side. It's just a guess, but at any rate I'll certainly plan better in the future and try to avoid feeling like that again!
3beans - I'm so sorry about your Dad, but glad that you were able to have a little more time with him than you might have otherwise had... I can remember my Mom donating often when I was young and always thought it was such a simple and wonderful thing to do. Its something I will do as long as I am able and I hope to pass on the habit to my daughter as well. ...and to age me, I looked at my donor record online today and my first donation was in 1989! Whoa!