Very few doctors really understand what ME/CFS really is and diagnose any example of chronic fatigue as Chronic Fatigue Syndrome. This saves them the trouble of tracking down other (potentially treatable) reasons for fatigue. So just because a doctor diagnosed it, doesn't mean you have it. If you have some other reason for your fatigue, you want it treated, not fobbed off as "It's CFS, there's nothing I can do."
This is true all over the world and is one reason why you DON'T want a CFS diagnosis if you can avoid it. It gives doctors an excuse to ignore you and refuse to dig further and find treatable conditions. It looks like you are already seeing that.
If I were in your shoes, I'd be objecting to the CFS diagnosis (even if I were pretty sure I had it) and pushing the doctor to look more deeply into OI and thyroid issues, both of which can cause fatigue. Even if you have CFS, getting treatment for OI and thyroid problems can improve functionality, but you have to get a doctor to look into that, which many won't do once they've slapped the Nothing-To-Do-About-It-CFS label on you.
If you are convinced you have ME/CFS and/or can't get a GP to treat you appropriately, it makes sense to try to see Dr Vallings. She should be able to diagnose and treat you properly.