Is there a way to get rid of infamy other than the Diplomat advisor?
I have over 20 infamy and my Diplomat is only a level 1 advisor, so he's only getting rid of a little bit every year.
Building an embassy will give you -0.4 BB a year. Having a ruler with a high DIP stat helps a lot, so switch to a republic with elections if you aren't already one. Build up your cultural tradition through cultural decisions, then use that to get a better diplomat. The curia isn't really an option because of that high BB, but each cardinal would give -0.1 BB a year. Getting rid of any unlawful imperial territory you have would be a good idea as well.