Once the topicals are stopped it will only take 24-48 hours for levels to plummet do to the half-life.
The only thing that explains your doctors low starting dosage has already been discussed in my previous post.
This isn't my first rodeo, I've seen this go on for years on this forum while the patient tries to rationalize why the doctor is doing what he's doing and it always ends the same.
Eventually the forum member snaps out of it and realizes his doctor doesn't know what the hell he's doing and starts the process of shopping for a new doctor.
I went through the same process myself more than once.