Oh no Badders you poor thing. I hope they are bringing you plenty of warm drinks and perfecting their sign language. 
I have been for my cardiology appointment today and for once came away from an NHS appointment happy. Lovely man, extremely helpful and willing to explain everything properly and by chance, was an electrophysiologist, rather than a cardiologist, who just happens to have an interest in pots.
Straight away he said he wants me off the bisoprolol and wants to put me on ivabradine instead. Apparently he's used that with several other pots patients successfully. I am really pleased, as I've read good things about it and only works on the sinus node, so doesn't affect anything but the heart rate, which means less side effects. I have read stories of other people having to wait ages to be allowed to try it or being refused it, so I was gobsmacked when that was the first thing he suggested. Just have to hope it's the right med for me now.
As I suspected all along, he said my blood pressure is normal/healthy and didn't need to be lowered further by beta-blockers, which is probably why I have been feeling so awful on them.
There are anomalies on my ECGs, both the GPs and the one they did today, but he said it's nothing he feels the need to panic about and may just be normal for me.
He was very interested in the EDS/hypermobility link, my Mum's recent echo results and the EDS/pots connection and referred me for an echo, both to check for any anomalies that might explain the weird ECG results and to make sure there's no EDS-type heart issues. He also made a note of my dcs ages to make sure they get checked out as well if necessary.
He's writing to my GP and told me to book an appointment towards the end of next week/beginning of the following week to see her about starting the Ivabradine. I'll be starting at a very low dose and he wants me to try that for 3 months, then he'll see me again and see if it needs titrating.
So, I am going to write to my private consultant tonight and tell him that I am switching my care to a NHS electrophysiologist and ask for a full copy of my file/test results and to cancel the appointment I have for a couple of weeks time, as there's little point in paying for it now.
I'm home again and absolutely wiped-out, but relieved and feel very lucky to have landed the right cardio guy. It really is luck too, as I was due to see a completely different cardiologist a month ago, but had to change my appointment due to dh's work commitments and ended up in this guy's clinic instead.