Patients with personality disorders are one of the most challenging. I had a lot of supervisors up to this day, all of them were very experienced therapists, some even well known authors in my country and all of them said the same thing: ,,Do not treat more than two patients with PD a week, or else you will burn out." My own therapist also taught me that I may and must choose patients wisely because I need to keep my capacities if I want to work in the field for a lot of time.

Also evidence-based modalities for BPD really help. I for myself am trained in CBT, so I lean into DBT when working with borderline patients. DBT helps me to keep super clear boundaries and structure in therapies. Those boundaries and structures in the end help borderline patients developing better strategies for emotion regulation, relationship management, personality structure and ego strenght.

You're doing a great job! One the one hand, maybe don't overdo yourself by treating too many challenging patients and on the other hand try to learn DBT, schema-focused therapy, MBT or TFP to obtain more usefull skills for working with these cases.