Sounds like you have a roaring metabolism. Are you still gaining weight?
It’s pretty normal to have insatiable hunger after an easting disorder but you’re right you were never so low. If your body felt starved from the restrictive diet, though, that could be it, though. Just for comparison, I was recently sick for a few weeks with low appetite and ever since I have been starving! Even a few weeks later. You were deprived for longer than that.
Agree on the protein advice. If you’re not eating enough of any macronutrient, it can make you feel unsatisfied. Your body should tell you this through cravings, though.
Also, bear in mind it could always be a medical issue, so if it keeps happening, a doctor’s visit could be in order.