From the OP and photos/description of the road, I'd say your time riding in the lane worked fine. It looks like there are more potholes and problems with the pavement than drivers, so road condition is more likely to determine your position than a motorist overtaking you every 5-10 minutes.

The double yellow is meant to keep motorists from passing other motorists going the speed limit without good sight lines. They need lots of space to pass someone going 40-60 mph. I've never heard of motorists being cited for safely crossing the yellow line to pass bicyclists, parked delivery trucks & buses, etc.

In your case, overtaking motorists won't need that much space to pass safely, but you want to stay far enough left to make sure they know to change lanes in advance. If you're in the center of the lane, this will give you more options to avoid bad pavement, and motorists see you there so I would keep using the middle, or best paved, section.