If you're tried cutting out meat products and diary is nearly impossible to avoid; if your diet and lifestyle are good and you still have an issue with odor, then it's time to seek out professional help. You need to consult with a physician and explain in detail how long you've had this condition, and what self help measures you've tried.
I know it's rather difficult and down right embarrassing to address Body Odor issues with strangers face to face, but you have to start being your own advocate. You have to be proactive and start helping yourself, no matter how difficult or uncomfortable the situation is. I wish you the best of luck. Let me know if you have any more questions.