Feel dizzy, headaches, vomitting after drinking green tea. no migrenes or any disease before. any reasons? could it be alergy to that tea ?

I doubt allergy: What else did you eat/drink aside form the tea? If you had other foods or drinks you could be reacting to the other foods. Food poisoning is possible. A non allergic reaction to the caffeine in the tea is also possible.

Side effects: You may be sensitive to the tannins and caffeine effects in the green tea. The concentration that you are using may be too high for your body to tolerate. Don't drink it if it makes you this sick. Use other non-caffeinated versions of herbal tea, preferably organic (pesticide free).