I totally empathize with you and your LPR symptoms. I was a professional singer, but lost my voice over a year ago. At its worst, I could hardly speak, but now have managed the symptoms so I can speak normally for short periods of time.
Your insurance won't cover GERD/LPR? Are you sure? Sounds like you're good with your prescriptions?
Unfortunately, you're going to need the EGD (endoscopy) to definitively diagnose your problems. During the procedure, you should also have a Bravo pH probe implanted in your esophagus to record reflux episodes over a 48-hour period. On top of that, I would also recommend upper, mid, and lower biopsies to test for eosinophilic esophagitis. Eosinophilic esophagitis commonly occurs alongside reflux, and the symptoms are similar. EE can be treated effectively, however.
Are you sleeping on an incline? That will help a little, but won't completely eliminate the symptoms. Six inches is recommended, but in my experience, twelve to sixteen inches is better. Don't mess with elevating the bed frame...just get those foam wedges from Bed, Bath, and Beyond. (Keeps the bed friendly for your partner, too!)
The reason the prescriptions aren't helping much is because they only reduce the stomach acid, but do nothing to stop the non-acid components of reflux, such as bile, etc. These can almost be as irritating/corrosive as acid.
LPR is a special complication of GERD. Not only is the LES weakened, but the pharyngeal sphincter too. The esophagus is tough enough to handle a small amount of reflux episodes, but not the delicate tissues of the throat, bronchial tubes, lungs, etc.
Some folks respond better to different PPIs, so it's worth a try to experiment with different ones. Be sure to check the manufacturer's website for coupons before going to the pharmacy -- it can save you a lot. I can't take PPIs because they cause massive headaches, but I experienced the most relief from Nexium. I tried omeprazole, Dexilant, and Aciphex too, but none of those worked as well for me.