You see Amy when I finally went to see a gp in the summer I had most of the symptoms you had.
I was told that I was just depressed and needed to go on antidepressants but I insisted on blood tests and like you only got the basic ones which really didn't show much. But in my heart I knew I wasn't well, it wasn't in my head something was wrong with me. I took hubby with me the following time and told her what made me think that there was more to do this than depression.She told my blood tests were "normal" but I kept insisting. I went in armed with a list of tests that the lovely people on this board had recommended. Somehow I managed to convince her to run a few of these tests and low and behold...yes I was right: b12 was low, ferritin and vitamin D were also very low and they could all explain my symptoms.
My antibodies although in range were on the high end so I managed again to convince that they would need repeating. I've just had them done and my antibodies have tripled which might indicate an autoimmune problem with my thyroid. I still don't have a diagnosis but they are listening to me now and have admitted that there might be a problem with my thyroid and that I need monitoring.
All of this to say...believe in yourself. If you don't feel right don't let them bully you into just accepting "it's just anxiety" as a diagnosis. Don't give up, change doctors if you can and if it really doesn't go anywhere maybe get some private tests done.