It's too late, unfortunately.
Sterilize all of your equipment, especially your pruning shears or anything you've used that has cut or trimmed that plant. After that, clean your entire room, lung room, floors, walls, the works.
Botrytis, contrary to popular belief, usually makes its way into the plant through a cut, break, or chomp from a pest. It rarely ever enters through the actual bud. It can also lay dormant throughout the plant's whole cycle, so it's hard to tell if the plant has it unless you have a lab to tissue tests or the plant shows that it has botrytis through typical signs.
Since your plant is showing symptoms, that means spores are everywhere. it could contaminate other plants that aren't even in the same room.
Just a heads up on bud rot. it's viscous stuff.
Good luck.