From memory and from when I took a lot of it decades ago, cortisol is the natural produced version, cortisone is the prescription one, also called prednisone.

When you take cortisone, your body reduces or stops producing cortisol. So if you want to get off the drug, you need to heavily taper it over a long period of time. When I was on it over 20 years ago and high doses, I would slowly go down to 20mg daily, watching any symptoms, and eventually do 20mg every other day and continue to lower from there.

Cortisone dependence is a real thing unfortunately, and it took me forever to get off it.