https://imgur.com/a/8Oc7H9V

Basically, I put drywall over top of of the plaster walls and now I have this issue where the drywall sits over the door jamb. Is there some sort of cornerbead I can use or is there a way to fill the gap and make it look like a smooth transition?

Before anyone criticizes, I know I did it wrong and should have tore down the plaster, but it’s a bit late for that now. This is my first time doing any type of DIY work so I’m bound to make a lot of mistakes.