The symptoms you described could be a number of things, but from my experience, you may want to get them to do a urinalysis on you and check your kidneys and make sure they are ok. I experienced some of the same things you described and it took them a while before they finally found my problem. I was extremely tired, lost weight and had lots of headaches. After doing a urinalysis, they found I was losing protein, which points to the kidneys and also protein is how we get our energy so that explained the being tired all the time. I was diagnoised with a very rare form of kidney disease, but am happy to say..I am in a remission right now and feeling great. good luck to you.