Chronic Cough 5yrs. Tried many things. What to do?

Sorry to hear of your health issues - I also have similar chronic coughing thought to be related to acid reflux.
My coughing feels what I imagine asthmatic related coughing would be like though I don't have asthma.

Do you experience burning/stinging sensations anywhere in your mouth, especially at night as I do?

I'm also interested to know how you manage to sleep upright - don't you keep sliding to the left or right and get neck pain?

I have the same difficulties with my electronic bed base that raises in two places - probably like yours. It you raise the lower half of the bed to stop you from slipping down it makes it almost impossible to lay on your sides.

And if you don't raise it, you slide down the bed and have to keep pulling yourself up throughout the night as you say, so it's not a very effective protection against rising acid. It's a Catch-22 scenario.

I developed back troubles from trying all the different positions this bed is capable of but thankfully nothing serious as I didn't continue - as soon as I noticed the first signs of back pain I reverted to a position less harmful. But then, that meant less helpful to acid reflux.

At the moment, I have the lower half of the bed down and head of the bed up just enough to position my torso higher than my legs. If the bed head is too high it creates too much pressure in the stomach area which can be counter productive - forcing acid upwards. I'm still monitoring the best use of the bed in this context and would be interested to know your observations as time goes on.

In my case, as mentioned in my post here titled 'Six Weeks Post Nissen Fundoplication' I only have acid reflux when falling asleep or taking a nap. If I was able to get by without sleep I would not experience acid reflux.

At all other times, my reflux is completely under control by using nutritional methods and portion control.