Wow! I certainly hope someone helps you soon, before you give yourself a concussion or worse, break a hip, etc during one of your falls/black outs.

Autonomic neuropathy can be treated by either cardio or neuro, but not all of either specialty are well versed in this condition, so you have to inquire about their training in the area. There are neuro who specialize in autonomic neuropathy, but they are few and far between...and probably even more so in the UK. Cardio's are sometimes better since the condition directly effects cardiac function.

There are several medications to help increase your BP when you stand...Florinef and Midodrine are two most common ones. Florinef is a steroid based medication to help your body retain fluid and therefore keep your BP that way. Midodrine is a vaso-constrictor that helps constrict blood vessels to push blood back up....that tends to pool in the feet in this condition.

Increased salt is always good, as is water, but it sounds as if you need MORE help then these two provide. Please contact one of your doctors and ask for more help before you really get hurt during one of these episodes. Also, I'm sure by now, you likely recognize that 'feeling' you get as your BP starts to drop. You need to immediately sit down when this starts...no matter where you are at the time. The faster you get down, the faster your BP will stabilize. Sometimes you have to get your feet above your heart, but sitting or laying down will at least keep you from passing out.

BTW, there are also medications available for the gastroparesis. In the UK, Domperidone is widely available and very helpful for this condition. Also eat small meals, walk after eating (so gravity and movement can help empty your stomach), and don't eat after 5-6 pm to avoid night-time symptoms. Sleeping with your head elevated may help too. Also avoid harder to digest foods like raw fruits and veggies (cooked/steamed is ok), nuts, etc.

So talk to your doctor about their experience with this condition...to find out which would be better able to manage your care. If neither has much experience, then request/search for another doctor that can help.