Rebecca,

As far as digesting meat, you may be jumping the gun on determining you can't after one bite in 17 years. It is my understanding that your type 0 body has the built in memory and ability to do just that. It may need some time to reawaken. In the mean time you could assist the process by trying HCL with pepsin or pancreatic enzymes before your protein meals. I too was a vegetarian for the better part of 15 years. Thought I was a natural at it but I always had health problems. I remember trying the Fit for Life diet with my wife. She was thriving and I felt like I was dying. I coundn't understand it at the time. I thought there was something wrong with me. Turns out she's an A and I'm and O. Now that I eat buffalo, chicken, duck, venison, and fish I'm healthy, ruddy, and thriving. As far as being a vegetarian 0 you may want to eat a good amount of vegetable protein and follow the other guidlelines. I don't feel Dr. D is telling us what to do. He is sharing with us his years of empirical experience what works best for all blood types.
As far as some early hunter/gatherers eating only nuts and berries, I'm not so sure. At the very least they probably ate insects. I recently saw a special on chimpanzees. From early Mutual of Omaha specials as a child I learned chimpanzees were vegetarians. Not true. They eat other monkeys with the fervor of the big cats of Africa. I give the chimpanzee example because reality seldom matches my idea of reality or what I've been taught about reality.
In response to your being irritated that Dr. D. hasn't responded to questions since November 20th, you may be more of an 0 than you realize. A good steak and exercise may end your crankiness for good. And I'm not monkeying around.

Best wishes for your well being,

Robert