You having wonderful d&ms - he would have loved being your soundboard, someone to offer advice to. Narcs always love the sound of their own voice & people who idolise them, as you obviously did. I agree he will have been learning what your insecurities are by having these deep conversations.
isn’t it funny how he was seemingly able to self reflect & offer you insight into his past, his parents, previous relationships & gave the impression he was emotionally intelligent - yet when he has done something hurtful it all comes out as excuses / defensive / dismissive of your feelings ? When push comes to shove he isn’t insightful or emotionally intelligent when it comes to anyone other than himself. He has no interest in analysing his bad behaviours with a view of learning & growing. They’re excuses.
They can wax lyrical on many topics but they are imitating a fake empathetic person. You’ve been had.
I think you want to be a good person & be seen as understanding, kind, generous, empathetic. However while these are good traits, they are destructive to yourself in this situation.
Making a list of every kindness you showed him & how he has chosen to repay you for it may be a start ? Find your anger ! It will help promise you that.
When a narcissist is done with you it’s called the final discard & it is very hurtful. He is going on with life as if it was normal - living proof you did not mean much to him, he did not care deeply for you & these people at their core are incredibly shallow. That can be why I think they pretend so hard to be these deep, insightful empathetic people - they know how deficient they are in human emotions. They mimic & copy because of their true feelings/opinions/motivations were known they would not be accepted by society.
One thing have learned recently is a covert / any kind of narcisssist will sometimes give themselves away by denying something verbally they are actually feeling.
Look at the situation with Myka Stauffer, the people who adopted the child from China so lovingly on their YouTube channel, then gave him away when he wasn’t fun anymore. In her videos she is often giving herself away eg” oh we have never thought of giving him up! We love him forever”
In reality they were thinking of giving him up
Narcs will often catastrophise - if you pull them up on one particular thing they may be grow their hands up & say “well I must be the worst boyfriend in the world then !” - they don’t want to address a particular issue & will make out like it’s a character assassination. They are terrified of having their TRUE character examined. The only one which they enjoy examining is the fake front they present to the world.
I am quite certain in his language there will have been “tells” which once you learn more about narcissism might help you see things in a different light.
I suggest any memory which confuses you because he seemed so sweet - go back & replay it with a critical analysis of what would have been benefiting him in that situation. They always have a secret agenda, ALWAYS.
Replay it & think “what was he getting out of that conversation / interaction ?” Because he will have been getting his narcissistic supply with you.
I don’t wish to upset you but he will have someone else on the go now & May have had an overlap with partners. They rarely leave until they get some form of better offer.