You could just "reprogram" your brain by shooting a number of shots until your point of impact moves up, but you probably already know that. If you decide to "reprogram," I would recommend doing bare shaft testing to locate your optimal nock point. If you're going to have to reprogram anyway, might as well get a better flying arrow out of the deal.
Alternatively, you could use a lower anchor point, which will raise your point of impact. Rick recommends the thumb knuckle on earlobe anchor, which for me is a lower anchor than the corner of the mouth (I have big ears). If you didn't want to change your corner of the mouth anchor, you could use your index finger in the corner of your mouth. This would probably raise your point of impact too much, but it sounds like you need to raise your nock point anyway, which would partially offset the lower anchor.