No, you are not overtrained, you are just carrying some larger fatigue. Not taking rest after a long and hard race was the first mistake. Donating blood will drop performance for sure. Heck, think about all the years of blood doping and cyclists putting more blood into their bodies for performance enhancement.
Some rest would be a good thing and I do not mean a TR recovery week. Those have a good amount of zone two riding in it. I’m more talking about a few days to a week off the bike if feeling really crummy and then a week or so of stupid easy riding. Adjust from there.
I posted a while back what real overtraining looked like in a thread. I’ll attach the link below but if you do not want to read an extended write-up, I can summarize a bit. Overtraining syndrome is something that takes you out of the game for years and takes a long time to develop. What you have described does not fit that definition.