"Back on my bullshit" is a phrase commonly used to describe someone who has resumed their previous negative or troublesome behavior. There are many synonyms for this phrase, each with their own unique flavor and connotation. Some alternative phrases you could use to describe someone back on their bullshit include "up to my old tricks," "falling back into old habits," "returning to bad form," "playing up again," and "regressing to my former self." Regardless of the phrase used, the common thread is that the individual in question has reverted back to their earlier behavior patterns, which may have resulted in negative consequences in the past.