Welcome to the GERD forum. There are lots of people here who've experienced the same symptoms you're struggling with. I'm sure you'll get many other helpful responses.
I think you could raise your bed a bit more. Have you checked out the bed risers at Bed Bath and Beyond? They're cheaper than the ones at a medical supply store, but they'd have them as well. I found a combination of bed risers AND a wedge to be the only thing that really worked when I was at my worst. Actually, I used the raisers, and added some boards under them. The only problem with the wedge, is that you can slide down, which puts your back into a bad position, and can cause it to hurt. I still used it for years.
Did you take the Prilosec about a half hour before dinnner? If not, you might try that. I always kept a bottle of Maalox handy. Also, a swig of water was very helpful.
Nighttime GERD symptoms is very common, because if you LES isn't working, the gravity that keeps the acid in the stomach isn't helpful when laying down. The acid can reflux right up into your esophagus when you're lying down. The fact that your symptoms are helped when sleeping in the recliner is pretty good evidence that your LES is loose and not doing its job.
I don't know of anything (other than the Nissen Fundoplication surgery--which I had on February 27th--and many others here have had) to get you back to horizontal. Joy (couchtater) here, is scheduled for an alternative procedure called Esophyx, which is very new. My GI doc didn't like the procedure, because it is so new and it doesn't have a track record yet. She's lucky enough to live in an area where there is an experienced surgeon doing it, so we're looking forward to hearing her story!
Best of luck in finding an answer to your GERD problems. We've all been there! Members of this forum will do their best to answer your questions, and offer support and encouragement. You're in a good place!