Cluster B has also been referred to in the DSM 5 as “erratic, dramatic” disorders. I stated this information and someone called me ableist, saying it’s stigmatizing and not every Cluster B disorder is dramatic (in some quality yes). What are your thoughts on this? Am I ableist? 

I think “dramatic” can be used objectively and negatively. I’m sure the DSM 5 was not trying to be stereotypical. I was also not using it in a derogatory way. Dramatic in itself is simply a word that can loosely describe Cluster B to distinguish it from the others.