I am a former nail biter, and because of it the nail beds have been pushed back quite a bit farther than they should be. Is there any remedy for this??

The nail plate will recede from the free edge due to the constant trauma it experiences from the biting. When the nail plate recedes, the exposed nail bed will harden and turn into regular skin. Once this happens, the nail plate will never be able to reattach to this portion of skin.