Humpty I feel for you, I lived with a guy for 4 years & it was pretty much the same with him - possibly worse as he was also a crook (tried to sell my house for cash to a builder he worked for) & he stalked me for months after I finally kicked him out
I was left with a lot of questions, over what was true & what wasn't & feeling so stupid for not seeing through it all, over & over in my head, drove myself nuts, it shook the very core of my confidence, because I felt I couldn't even trust my own instincts any more.
The stalking thing was done in such a bizarre way (things like breaking into my flat at night & quietly moving my furniture around, or stealing 1 shoe) I the Police wouldn't take it seriously & actually started to question my sanity & THAT pushed me to seek counselling - it was the best thing I ever did
She made me realise that it was him that had mental issues, not me & that in believing in him I wasn't weak, or stupid, but that he obviously had a deep seated personality disorder & believed in it himself, she helped me to see, that by lying daily about inconsequential things, that made absolutely no sense but to believe in, as no point in going to the trouble of lying about something so silly, he conditioned me to question my instincts, so when the big lies came I automatically didn't trust my instinct & believed him
I suspect this is the same with you, because this is how these people work - that doesn't make you weak or stupid, nor them clever, just very very damaged in a way that you have likely not dealt with before, so you were ill equipped to see it for what it was :)
see if you can book a few sessions with a recommended counsellor, its not weak to do that, but it will help give you coping techniques & help you see it for what it was & move on :)
I still don't know most of the answers as far as my exes past goes, what was truth & what was lies - his name for example wasn;t even real - but it doesn't matter one bit to me now, it won't to you either in time & IME counselling can help that time come sooner
good luck :)