It sounds as if you have a stuck shed. If your using a cheap analog hygrometer it has probably been giving you false readings.
I would mist heavily and if you have some moss I would add it to each hide. Make the moss damp and place it in the hides. This will create higher humidity in the hides that will benefit the snake most since the hide is where it stays most of the time.
Another thing you can do is place a damp towel in the cage and let the snake crawl through it. The snake knows what it needs and knows how to shed. Do not help the process as you could pull off good skin with the old skin and create a bigger problem.
If your humidity has been a steady 65-70 you should get a nice single piece shed. It should not be flaky.