OK help me out here. I read through the section DMG and don't understand why a Wish is necessary. It speciically states if you embrace the curse you gain full control over it. Nothing says that while shifting when in control that you lose it. There is only a reference that those who reject the curse and never shift will do so involuntarily on a full moon and if this causes an alignment change the DM *might* decide to control your character then until it reverts back. This only happens for those rejecting the curse which the OP isn't.

If you're embracing the curse, you don't need a wish. You control it and yourself.

I'm also going to stress the DM only takes control if the alignment of the shifted form is different than the character's normal alignment and only if they are rejecting the curse.

A werebear's alignment is Neutral Good which is perfectly fine for a PC, and you're accepting the curse. You should never be losing control.

Rather than Wish just speak to the DM and say you're happy to play a Neutral Good character - and quite frankly the DM taking the character off you to lose control would be a ******* dick move, to be honest. There is no reason why you cannot play your character as a Neutral Good Werebear. I see no reason why you would be losing control or need to make a wish unless your DM is an ******* that refuses to work with you for a fun experience.