TW: abuse, self harm mentioned, and doubting my diagnosis

I was in a relationship with someone who was emotionally and verbally abusive for 9 years. He would threaten to leave me, to kick me out, or to hurt me/himself to get his way, amongst other awful things. I only bring this up because I got diagnosed with BPD (not Quiet BPD) while I was with him and now that I've left him some of my symptoms are significantly less intense. I'm not terrified that I'm going to be abandoned, I don't feel empty anymore, my self confidence has skyrocketed, I'm pretty sure I haven't split since I left him, and I'm no longer self harming. Also when I was splitting, it was always directed at myself and mostly while he was screaming at me or directly after. 

I guess what I'm trying to say is, what if I don't actually have BPD? What if I was just being abused and my reactions to said abuse mimicked BPD symptoms? Is that even possible? Or am I just in denial?