I know many people do just that - start induction after going off the plan. I don't think you have to but what you should do is to cut all fake and SF foods (if you are having them) and eat lots of protein and fat plus low carb vegetables. Try to eat legal foods you really like, it should help you survive the first days.
I've never been in this situation, maybe someone else will have a more precise advice...

Good luck

Alina