Oh no no no.. what did I do

I have seriously messed up.
I was staying away from the ex boyfriend, going to counselling, moving on, gaining strength, understanding my triggers and the way he 'grooms' me and last week when my medication was doubled and I was lonely (yes I am going to use that as an excuse because I'd been brilliant for a few months) I got a message from ex b asking me to meet him for coffee, so I said ok then. When it came down to it, I didn't go. I stopped replying to messages again, didn't answer the 300 phone calls, except one (I'm so stupid) and today I get an email that is just pure evil....The subject is "I know you now" And this is some of it..

"thanx for waking me up to the person that you are.

you don't email me. you deleted me from msn. you don't message. you don't call. you're not interested in counselling together. you couldn't be bothered to meet me the other day for coffee.
I called you on friday night several times, messaged you with no reply. i called on saturday, messaged you. your excuse was that you left your phone at home. it obviously wasn't important enough for you to keep your phone with you incase i messaged or called over the weekend.
you just deal with your own pain and fuck everybody else.

no you're not missing me at all because you are too wrapped up in yourself. I hope that works for you.
you lied about loving me. i see that now. you just wanted me as someone else that you could blame, because that works for you.

I thought i'd keep in contact because i love you and i didn't want things to be left like this. i thought we were both better than this. now i know that you're not. I was stupid for thinking that you cared. I hope you can get yourself sorted out at counselling. I hope you can be a better person.

There's more about me supposedly berating his children. He said I lied about his daughter saying that she didn't like being with him because of his anger, which the poor girl did say, and he goes on to say that I will start saying nasty stuff about his youngest son who I really cared about...

Anyway, I was furious when I read it and I didn't stop and breath and think, I just called him and my first words were "How dare you"
He swore at me and put me down, I kept my cool and was strong with my words, until he said "Do you want everyone to know about you?" I didn't understand what he meant, and then he said "The truth will come out about you" I said "What? are you threatening me?" and he said it again "The truth will come out about you" and again I asked if he was threatening me and he said "Yes" well my blood ran cold, all I can think of is that he has certain photos of me and a video :( I am disgusted with myself for getting into this situation, if I didn't do things he wanted I was berated, it was just easier to do it.

This is a man who made posters of his ex (who he has 3 children with) and stuck them to poles and I think he put them in letter boxes near where she lives, granted he did it because of the state of the house where his kids were, and the posters didn't have her face, but this to me means he's capable of anything.

There are so many "what ifs" I just have to suck it up and have faith that now that my path is going in a positive direction, if anything happens I have the strength to hold my head high and deal with it with dignity... I just wish I was thin in the photos and video (trying to find a lighter side)