I'd look into having an adjusted mouthpiece, because the pain shouldn't be that bad for that long. Maybe an adjustment period, but not misery. You can check with a qualified dentist too - they often work in this area.
I do feel, though, that you should go back to the CPAP if you have to. Sleep apnea is more than just annoying to the spouse. You're not getting the rest that you need, no matter what you think - you're not getting REM sleep and that means you are not getting any restorative of healing sleep. You will, over time, be a health risk for many other conditions, and you (and your husband) are absolutely both risky drivers. Fatigued driving is a huge cause of accidents. Don't mess around with it. Who cares what it looks like when you turn the lights off? I've been there and I know. I tried mouth guards and now just realize I need the CPAP.
Another factor in obstructive sleep apnea is weight gain. If that's a problem for you, it's an added incentive to lose weight which can reduce the size of the tissues inside the mouth, and help alleviate the problem (although not always completely).