How do you tell the difference between symptoms coming from bipolar disorder and symptoms coming from borderline personality disorder?

I am going to be starting medication soon for BP1 with psychotic features, but my concern is that I had a pretty abusive childhood, and issues with abandonment and invalidation were pretty common and severe.

So what I don't want to happen is for me to start taking medication for bipolar symptoms, have unresolved issues that I need to work out but not realize it and just keep trying to medicate them away.

My understanding is that the emotions from BPD do come from somewhere, it's just a matter of trauma and trying to figure out the true roots of the issues. Whereas with BP the issues and symptoms are manifested from chemical issues and whatnot, apparently, so the emotions and thoughts are more so random and meaningless, albeit highly problematic.

I don't want to just medicate away emotions that do come from somewhere and need to be processed, but I do also need to medicate away the bipolar issues because they are chaotic and random.

So how do you tell the difference?