@toastedsandwiches I really feel your pain, it's coming across in every post. You are not alone though, so many of us have been where you are and we understand, please don't blame yourself.
I would echo what other posters have said about education - that is what really helped me. I came out of a 13 year abusive marriage and did the Freedom Programme, but I didn't realise necessarily that he had been a Narcissist until I had a (much shorter!) relationship with one. I started counselling and it became apparent that both relationships were with Narcissists, just different types. The fact I got out of the second one within months showed that my boundaries were far far stronger and the impact on me that time was therefore minimal.
The thing with this kind of abuse is that you cannot believe that there are people out there genuinely capable of this 'evil'. The fact is that there are. Some are aware of their behaviour, the vast majority are not though - not that I am excusing it at all, but they aren't deliberately out there plotting, but this is a very real, very destructive disorder that makes them behave like this in order for them to function.
When you think of the good times, replace the times he said 'I love you' with 'I use you'. If he ever said 'I've never met anyone like you before', replace that with 'I've never used anyone like you before'. This is REALLY what they do, though they often don't see it like that. They aren't capable of real love, they create a facade of it, and, brutally, we fall in love with that facade. The love we feel is a reflection of what they have conjured up, and they get so much energy from that love mirrored back to them. They are emotional vampires. And you have done nothing wrong.
Please educate yourself - watch the HG Tudor videos online, they are amazingly insightful and truthful, you will have many 'A ha!' moments. Get a counsellor who specialises in Narcissistic Abuse. But, I would say the most important thing (which applies to anyone tbh) is to build a life for you that doesn't mean you need anyone else in it for validation and happiness....then if you meet someone amazing then great, but if not, then great. You will be less vulnerable as a result to anyone then - whether just general time waster or a malignant narcissist, or anyone else in between.
And practically speaking - if you are insured on his car/have a spare key - I'd just move it to somewhere else in the road?