You don't consider being lied to, cheated on, and semi-accused as being abusive or devalued? Just consider that.
I'm not ready to risk being devalued, yet. ... .
I've been really thinking deeply about my relationship since finding his sext messages, and searching to find what it is, that keeps me from walking away from a boundary I thought I had. I just keep coming back to the same conclusion, I've never been given this much love and affection in my life, and I craved this so much when I was little, maybe he is fulfilling something inside me.
Completely aside from what you decide you want in this relationship, you really need to consider where you're coming from as well. Being in a r/s with a pwBPD isn't easy and you'll need a strong sense of self as well as good emotional self-regulation. You've stated that you're using your BPDbf to fulfill a void - that's not very validating for you and it isn't a long term solution to your emotional needs. If this is truly the case, I'm concerned that you aren't 'in love' so much as you are 'in love with being loved' (which makes sense, and I don't blame you, but they are very different things). If/when his cheating goes further are you at risk of being even more hurt because of this dynamic? Please be careful with yourself.