To get the full picture of thyroid function you need to have the following tests done
TSH
free and combined T3
free and combined T4
Also the British Tyroid assoc recently admitted that at least 25% of the people who give the blood samples have undected hypothroidism.
The problem seemed to me to be that gps would rather give out ads or tell you that it's your 'hormones' or your age.
A couple of other symptoms are
a sort of muscular stiffness (as is they won't get moving after you get up from a sofa),
the outer part of your eyebrows being missing - I was so tired that I was just glad that I didn't have to pluck them,
your tongue feeling almost too big for your mouth
anyone else in that family having thyroid problems, or pernicious anaemia, diabetes, sarcoidosis, neutropaenia or any other of the family of auto-immune disorders
also (in the US) laft-handedness ups the risk.
Also having had a whiplash injury can injure the gland which, in turn, can cause problems. This is why I feel that anyone having such an injury should have the full range of thyroid function blood tests done so that they have their own personal baseline for comparisons.
As you may have guessed, I have an underactive thyroid, which I think was caused by several whiplash injuries. I also had to fight for years to get treated. One of the gps gave me an odd look when I asked her if she had thought of the hidden social costs. After all if relationships break up because a partner thinks that their dp can't be arsed to do things when it's rather that they want to, but just feel as if they're recovering from flu, and so haven't the energy, there will be consideral costs, both monetary and emotional.
However, dh has sarcoidosis, mf had pernicious anaemia and his sisters were hypo, and mm, gm and an aunt all had nodules removed. I was very keen to get a diagnosis and dd will have inherited a tendancy for this sort of illnesses from both sides of the family.
Good luck with getting the problem sorted.