Sorry, somehow missed your post; I’ve put it in a general category so it might get seen more!
Firstly, I’d suggest if you have time before Thursday I’d read through the Newbies Guide section on symptoms & what causes them; it sounds like you could possibly have vascular ES from some of your symptoms, it can cause cardiac arrythmias, & also so can vagus nerve compression/ irritation.
The headaches, eye pain & blurred vision can also be down to vascular ES, either compression of the carotid artery or the jugular veins can cause those symptoms.
A CT with contrast will show if there is any compression of blood vessels, so you could push for that.
I don’t want to scare you, strokes are extremely rare with ES, but in order to get the doctors to take you seriously, you could print off the research papers referenced in the Newbies Guide section about this. I’d certainly print off any which support the symptoms you have.
And lastly, we’ve had quite a few members from the UK who have had successful surgery with other doctors, so as Julia says maybe consider asking for a referral to someone with more experience if you can travel. Mr Axon at Addenbrooks in Cambridge is the most experienced, & there’s several others on the doctors list. The 2 nearest doctors to you, Mr Saunders at Bristol I think possibly does intra-oral which might not be best for you with your symptoms, & Mr Corbridge in Reading doesn’t seem to be quite so keen to do surgery recently, just to save you wasting time!
Let us know how you get on Thursday!