Issues that make me want to ctb are my processing issues (not always being able to understand what people are saying), my bad short term memory, my inability to articulate myself verbally sometimes. My diagnoses are Bipolar 1, BPD, PTSD and anxiety. I think it might just be my depression causing my motivation issues
If by "BPD" you mean "Borderline personality disorder" (I'm asking because it can also refer to "Bipolar disorder"), then there is an issue with your current diagnosis as it doesn't really make any sense to diagnose someone with both Bipolar disorder (either I or II)
+ Borderline personality disorder. Bipolar disorder shares some similar symptoms with BPD (for instance,
emotional dysregulation). Also note that PTSD and BPD are related in some ways (traumatic events during childhood can potentially lead to both).
Now, depression is symptomatic of both conditions (Bipolar I and BPD) and as you said, lack of motivation can be a symptom caused by depression (among many other things). But either way, symptoms of depression and lack of motivation can be treated
or drastically improved with more appropriate medications than the ones you have tried so far.
As I said in my previous post, none of them actually improves motivational issues and you should probably ask your current psychiatrist or find a new one that will take the time to understand your issues and find a treatment that works for your depression (and thus, increase your motivation).
Another thing: your "processing issues" (not always being able to understand what people are saying, bad short term memory and inability to articulate yourself verbally) may be caused by your current medication (which could be inappropriate or not properly suited).