Well done for having more productive days.
This stuck out to me -
I'm really stuck,I felt as long as he wanted me,found me attractive I was worth something.
Now he's decided I'm not worthy of even friendship..I'm nothing again.
Unfortunately, while you look to other people to make you feel worth something you are going to be a prime target for just this sort of person. They can spot that vulnerability from a mile off and enjoy playing about with it.
There truly is nothing you could have done to make him behave any better - if you were more confident and had better self-esteem he would probably not have bothered in the first place. Or he would have worked even harder to destroy your confidence. But he sounds more the type who prefers someone vulnerable who he can mess about.
It's a power trip to people like this - evidenced by him sending you those messages about other women and trying to wind you up.
Please try and do some work on your self-esteem. I don't think it's necessarily true that you can only find love once you fully love yourself, but in all honesty, when you place so much of your self-esteem on whether someone else wants you it's going to do two things.
Firstly it is going to make people looking for a healthy relationship run a mile because they will understand they cannot possibly be the whole basis for you thinking well of yourself. Secondly, it will also attract the type of predatory assholes like this idiot.
This guy may or may not be a narcissist, but it's more about how he has behaved. No-one who is a decent person would behave so cruelly. If they had decided they didn't want a relationship they would say it with grace and not go out of their way to be cruel.