Okay, I think I can help answer some of your questions and give you a bit more insight into what is happening.
For starters, the symptoms of BPD manifest themselves most around the people who are most cared for by the person suffering with BPD. A lot of people struggle with understanding this part. People with BPD will often hurt the people they care about the most because those people have the capacity to hurt the pwBPD the most. Does that make sense? When someone with BPD truly cares about you, you're in a powerful position where they fear you will verify all of the negative things they feel about themselves while also hoping you will prove all of those beliefs wrong.
As much as someone with BPD wants intimacy and a real connection with someone, those things are very, very triggering to them. That should be understandable because inside of these people are feelings of being inferior and unworthy of love. If you truly felt like that, how comfortable would you be around someone who did love you? And would you trust that love when you "know" you're unworthy of it? You'd likely be worrisome that it's only a matter of time before they figure out how inferior you are and then leave you ... . like you're sure they will do because "everyone always does".
We have to remember that someone with BPD is highly skilled at wearing a mask and assuming different identities. So it really doesn't matter how they appear to someone else. In the case of yours looking "happy and cheery", it's doubtful that they really feel that way inside (unless they are dissociating).
With the conversation you had, I potentially see a couple of things:
1)You are selfish and spiteful
2)You want to control everyone... . people think you are nice but it's just because you are manipulative
3) You have made me out to be unfaithful when you know I hate that ( this had never happened)
These could be simple projections; things he feels about himself but are projecting onto you.
Other stuff you wrote (that they had said) appears like it could be projective identification. How that differs from a regular projection is that it causes the person whom these false beliefs are being projected upon to change their behaviors thus making the beliefs true,
Imagine, if you can, someone shouting and hounding you about how horrible, cruel, and mean you are. That you are abusive and have anger issues. And imagine they don't stop. They keep pushing and pushing and pushing until you actually are angry and then they say "See? You are exactly what I said" and they push some more until you do lash out at them in some abusive manner. That is projective identification.
The worst part of it was that I could see that he had a genuine belief in what he was saying.I struggle to understand how he could have developed these views based only on times when I have tried to rectify misunderstandings.I am starting to question my own behaviour and sanity.
There are two BPD symptoms that may help you gain some perspective:
1. Dichotomous Thinking (All-or-nothing / Black & White thinking)
2. Lack of Object Constancy: The ability to perceive an object as unchanging even under different conditions of observation.
For someone with BPD, they often read each action of a person as if there were no prior context. You could have said the most loving, endearing thing to them an hour earlier but, in this particular moment, they were triggered by something and believe you might not love them at all.
The dichotomous thinking prevents them from seeing a range or spectrum. They don't understand that good people can do something they perceive as bad but still be good people.
When you combine the two, you have a thought of "this person is bad" with the inability to draw from memory those good experiences and grand perceptions of that same person. All you have is that current moment - which feels bad and dangerous.
So yes, he DID believe what he was saying because that was his "emotional reality". Often times someone with BPD will later realize, while emotionally regulated, that some of their thoughts were likely untrue and they then become over-run with shame for having such thoughts and treating someone else as if those thoughts were true. Some will apologize; many cannot - due to the shame involved and how that shame validates their own negative self-image.
I'm sure this is very difficult on him as well but BPD shouldn't excuse anything. Just because someone has a disorder, it doesn't mean they have a free pass to treat people poorly. It means they should be seeking help and learning more effective techniques to improve the quality of their lives and relationships.
Anything I wrote isn't an excuse for him. It's for you to understand it and hopefully be able to depersonalize some of it (which I know is hard to do).
