Do I have ME or CFS?

Hi everyone, I’ve just joined the community and would love some advice on ME and CFS!
I’ve experienced chronic fatigue for the past 8 years and it's gradually got worse and worse. After moving house 2 years ago I joined a new GP surgery. I’ve been there a lot, with multiple problems, and yet I’ve never seen the same doctor more then once (many are locum). It makes it hard to build up any kind of relationship with a doctor and even harder to get a diagnosis.
After years of blood tests and seeing lots of different doctors, I was finally told by one a few weeks ago that I have Chronic Fatigue Syndrome, he said this is also called ME but they are the same condition. However because they found I am deficient in Vitamin D, I cannot be referred to the ME/CFS clinic until that’s at a normal level.
So why am I confused? I’ve read that CFS isn’t actually a diagnosis of anything. It’s a “we don’t know what’s wrong or causing these problems” and should only be given when a person has no other conditions that could cause fatigue. But I also have Functional Neurological Disorder and Irlens Syndrome, both which can cause fatigue. Vitamin D deficiency also causes similar symptoms. This is confusing to me, is it possible to have CFS if you have other conditions that can cause fatigue?
When I’ve looked online there seems to be people fighting against the idea ME and CFS are two names for the same condition. Many say they are completely separate but lumped together because they have similar symptoms. I have read that ME is not a diagnosis of exclusion, where CFS is. There also seems to be multiple differences between the two conditions, mainly the cause of them. However, I spoke to someone at ME association who said “There are no clear pathological markers that separate ME from CFS.” He also said you can have both.
I am very confused! Do I have ME or CFS? Do I have both? Or are they essentially the same thing?
It is incredibly difficult to get a appointment at my doctors surgery, recently I have been told I can’t book an appointment and I need to go to drop in in a morning if I want to see a doctor. That involves waiting in the surgery for hours and sometimes I just am not well enough to do that. And the doctors I have seen don’t seem to know the ins and outs of the conditions and the possible differences between them. I do see a neurologist once a year, but I had my annual appointment a month or so ago,and to be honest the neurologist was pretty unhelpful. Appointments are very rushed and I’m simply told there is nothing they can do for me. And until my Vitamin D improves I cannot be referred to the ME/CFS clinic! So I’m in a bit of a pickle and would love some advice. Thank you!
Replies
Are there any specific questions I can help with? My brain isn't firing on all cylinders lol so I can't remember what else you needed help with. The ME Association is a brilliant source of information and they have a helpline too.
I think my question is based on the idea that CFS isn't a diagnosis of anything, I've read many articles on this. So many say it's what doctors diagnose when they don't know what's causing the symptoms, and that worried me because I have other conditions that can cause these symptoms. I'm still finding it quite confusing because people have so many different opinions on the condition/s. Yes they are, I spoke to a doctor from the ME association, he was very good at explaining everything to me but still said it was complicated as there are still different medical opinions.