Welcome! Sorry to hear of your problem about your throat! Are you seeing an specialist such as an ent(ear, nose and throat) Dr., maybe you might need a second opinion, I am no dr if you feel week and tired a lot you could also have mononucleosis(sp), their are also a lot of immune situations going on, bugs, viruseses(sp), allergies and it could be your tonsils. I do know that when you have chronic sore throats you do need zinc and it is easy to become dehydrated because it is too difficult to swallow with your throat being irriitated. My opinion is that you do need to see a specialist until the problem is resolved. Also gargling lightly with salt water can help sometimes too. You also might check and see what the health food/herb shop and see what they reccommend too.
Good luck!
Keep us posted on what you find out!