You have empowered this manager to treat you this way. You need to wake up and be accoutable. Every pc. of advice, you defend his/her actions and we are trying to give you advice to change your reality. The reality may be this is your comfort zone.
You are already on the managers bad side-so, so what.
You are already a target- so, so what.
You are already stressed out-so, so what.
You need to let the manager know that you do have a clue that this treatment is extreme. You do have the right to let him/her know that you look forward to seeing them on (date and time that will be exactly 2 weeks from today's date) because you are more than happy to re - route your territory to accomadate his/her schedule and maximize your time with him / her as you work on ...XYZ (that has been documented in your field ride-along report).
Bump-asking why. Point his/her butt on notice, bullet point your observations, provide action points that will be solutions to the problem. If there's no problem, s/he is on the defense - and very well should be.
I think you need to go handle your business.
BTW I am a former rep-now a manager. I speak from whence I know. Never compromise the integrity of who you are. You will look back and hate yourself for giving away your power and your pride to someone else.