This is not a tough question.
To sum: "My DM is making up rules and forcing my character to do things. I play a class with alignment consequences. Can my DM make me evil by making me do evil things with his made-up rules?"
If the DM wants to have you lose your powers, you will lose your powers. I would have a hard time of it, but if you can trust your DM, who creates rules at his whim, to be consistent and fair in his adjudication then you are OK. Otherwise, you might be in the hands of a DM who wants to remind everyone who's in charge.
To sum: "My DM is making up rules and forcing my character to do things. I play a class with alignment consequences. Can my DM make me evil by making me do evil things with his made-up rules?"
If the DM wants to have you lose your powers, you will lose your powers. I would have a hard time of it, but if you can trust your DM, who creates rules at his whim, to be consistent and fair in his adjudication then you are OK. Otherwise, you might be in the hands of a DM who wants to remind everyone who's in charge.