Do i have thyroid problems?!

[SammyP]

I'm a 27 year who has always been extremely sporty since the age of 6 playing competetive football at a high standard. Since Dec 2008 my health has deteriorated and i have been unable to do any exercise without feeling awful. I feel i have lost the ability to sweat and become extremely lethargic after any exercise. Sitting in the sun makes me feel bad too, almost like im dehydrated and can't regulate my body temperature. I have all the symptoms of diabetes, frequnt urination, excessive thirst, lethargy etc but have had tests and nothing hs come back. I also am on esomeprazole to settle my stomach which has had gastrisitis for nearly 6 months on an off, and although i dont get heartburn as such i do get acid reflux in my mouth. Is it an allergy to foods or do you think i have something wrong with my thyroid?? What could anybody suggest i do, as i want to get back into sport and am going to the maldives in 3 months for my honeymoon??

[gimel]

What tests were done and what were the actual results and reference ranges?  If it were food allergies, would it change so much lately?  If you haven't been tested for thyroid issues, then I would suggest testing for free T3, free T4, and TSH.  And since your health has changed so much recently, maybe I would also include antibodies tests for autoimmune system problems affecting thyroid.