First let me say that I am no expert in the field of bloodroot. However, I started taking black salve tablets about 2 months ago (which has bloodroot as one of its main ingredients) and received quite a bit of helpfull advice from a local vitamin store owner. He said that if you get sick, queazy, nouseous etc...from taking it, it is a very good sign. He said that means you really need it and that you are killing off a lot of bad guys. If you need to drop the dosage and slowly work up to a more standard dose than go ahead and do that.
My personal experience was I immediatly had a huge flare up in my skin problems and got extreme flu/cold symptoms with fatigue for 2+ weeks. I would be nouseous for about 1 hour after taking each dose. After 2 weeks everything got a lot better and I had 4 weeks of extreme healing. I'm 5 weeks out now and am recovering from a few days of more flare up. I've been told that it's normal for the body to heal itself in layers and not to worry if symptoms return like this a few times. I no longer get nouseous at all from the pills.
My advice to you is stick it out. Reduce the dosage if you need but don't give up on it.