My lower tooth started moving after wisdom teeth removal. What should I do?

Hi doctor,

Around six months ago, I removed four wisdom teeth (one tooth per month). I remember the first two were not very painful, but the third and the fourth ones, especially the fourth, gave me really bad headaches and it even made my whole cheek swell for a few days.

Anyways, I also noticed this one tooth from my lower teeth started moving after all of my wisdom teeth were removed, and so I started putting on my retainers at night, but the problem is that in the morning when I eat, that tooth starts moving again and I get a headache eventually during the day.

My orthodontist told me that there is nothing wrong with my retainers and that this headache could be caused by me grinding my teeth at night. I have also been told to do a CBCT scan.

Any suggestions on what I should do? Should I go back to wearing braces on my lower teeth?