Hello~In my younger years, I dyed my hair constantly, it is a wonder I did not go bald, I had some breakage, but nothing serious. However, I think I am one of the rare people, but that being said, once the chemical reaction stops, the roots can begin growing again. It may take a month or so, but you should start noticing some growth after that. Try using some hot oil treatments, this has been known to help as well.
Back in the day, and I'm aging myself here . . . I had something similar happen due to a strong perm improperly applied. It sizzled my hair down to my root. Not everywhere just around my face. :-0 It was not a good sight. But I recovered and the hair did grow back for me. I have read to stay out of the sun. The sun weakens it even more while you are trying to recover. Try not to blow dry and air dry instead. Take a health supplement with biotin and niacin in it. Choose a shampoo with botanicals and essential oils in it. Maybe this article will help as well. https://www.dermatologytimes.com/dermatology/what-causes-hair-loss-after-permanent-hair-dyeing There big advice is to do as little as possible to the hair during this time. As little brushing, combing, dying, styling, etc. as possible. Hang in there. (hats are also cool right now . . .)