BPD is always coupled with other disorders (depression, anxiety, PTSD, etc.) most of which are treated by medication. If you have obsessive thoughts, there are medications that can help with that. I take Latuda for my SUI and SI thoughts. It helps. I also take Ativan PRN when I need extra help.

There's 3 types of SI. Stereotypic is what you would see in autism: rythmic head banging. Superficial is the type of SI that is common with BPD: cutting, burning, etc. The third is Major which includes things like amputation and is associated with psychosis. There might be a 4th if you include the OCD types of trichotillomania and dermotillomania.

It's just my opinion, but I think you'd be considered major
. Your SI is extreme. It's not superfical for sure, and it's not like the common OCD SI. And maybe itis due to psychosis? Could explain why you're not finding any relief from therauypy and common meds. Have you tried any anti-psychotics? That's what Latuda is.l

I'm not trying to diagnose you btw. Just giving you info that might help you along your path.

I do wish you well.