What Should I Eat?

I noticed that whenever I eat beef, pork or prawn even along with my normal diet of  75% vegetables and fruits, I will experience some kind of skin itchiness on both my legs later in the evening. This will not happen if I eliminate pork, beef or prawn. I try to prove myself wrong by keeping track of what I eat and see what happens. Initially, I thought it must be some bed bugs or perhaps some plants that I came into contact with when I do my gardening at the front yard. Anyway, based on my record, the culprit seems to be the food! This got me thinking about what Dr. D'Adamo says in his book. He mentioned that blood type 'O' person can take beef as this meat is medicine for this group of people. However, I believe that my body reacted negatively to beef because the quality of  beef that we take nowadays is way below than the meat that our forefathers enjoyed. Those days, cows feed on green pastures but now the livestock industry keep all the animal in overcrowded condition. Crammed together, the cows are force-fed by processed food so that they grow fast and become fat. As these animals are not destined to live in such condition, to keep them alive, the industry put them on growth hormones, antibiotics, drugs, etc. No wonder my body is reacting against this meat. So, no more beef for me please... unless if I can find 'organic beef' which is very hard to find and is expensive. Dr. D' Adamo also mentioned in his book that pork is 'poison' for blood type 'O' person. Yupp....I have cut down eating pork to almost zero! As for the prawn, it is listed under neutral which means it is just food for blood type 'O' person i.e without giving any beneficial health value. Anyway, I read some articles that say prawns are highly toxic as they are scavengers or in other words they are garbage collectors. They eat fish droppings, dead creatures, dirt (anything that is edible to them!)... and their job is basically cleaning the water. So, their tasty meats are full of germs and toxins! (sob...sob... prawns happen to be one of my favorite!).

Frankly, as I learned more on what type of food I should eat to be healthier or to be free from disease, I found numerous contradictions in the nutritional research. There are just too many theories or findings that are contradicting to each other. Some studies support the idea of being a vegetarian while other says that a high protein diet is the best diet. Why did some herbs do wonders for others, while some don't even feel any improvement when taking them? Don't you think this is frustrating??