Please someone help

I'm very new to this so please bear with me!

I've just been discarded yesterday by my N for the third time in eight months. I hadn't heard from him in 3 days and I could feel that he was pulling away from me again. I challenged him about it and apparently that was enough to kick my to the curb again. "You seem to want constant reassurance from me", "We've been here before and I'm not doing it anymore!" - I don't think I was asking for much, just a bit of consistancy and to know where I stand.

After that I really told him what I thought (all through text as he refused to answer the phone)and got no reply.
I feel confused, used and lonely.

I don't think after the things I said he'll be back and for some reason that is terrifying me. I know he's probably done me a favour and I should be glad that I'm shot of him - he's poison. However, the thought of him not being in my life is killing me. I've even considered contacting him to beg for forgiveness for something I haven't done.

Please someone tell me where I go from here, its only day one and I already feel like giving up.