Back again...

I joined the forum last summer after being discarded again by my ex N.
I thought I was starting to wise up and understand what I was up against with him but I was wrong. He successfully sucked me back in and I barely put up a fight. In fact I think I felt relieved that he was back.
In September, he made the decision to move out of his flat and move an hour away from here, into his aunties house, to be nearer to work. At the time my son and I were staying temporarily at my mums house as we were in between places. I was looking for a new place and his place was perfect.
He suggested I took over the tenancy and was unusually happy that the landlord accepted. I thought he was pleased that I was sorted but now I realise that he had me exactly where he wanted me.
He continued to come down to see me, letting himself in with his key, still referring to it as his place and made sure he left most of his belongings here. I've even been left with his cat!
Things seemed great for a while (the best they've ever been anyway!)he was coming down most weekends and I went up to stay with him.
Everything changed around my birthday in November. He had told me he was coming down to take me out for dinner. The night before my birthday I received a text to say he couldn't make it. I was really upset especially as his birthday had been a few weeks before and I had made a lot of effort. He said he was really sorry, he had to work late and he'd make it up to me that weekend - I was planning to stay with him as we had a football game to go to (his birthday present from me). On my birthday I didn't hear from him until lunchtime. No phonecall, just a lame happy bday text.
I let it slide like I always do and focused on the weekend together.
That weekend seemed fine, we had a good time and he was really sorry for letting me down on my birthday.
I barely heard from him the week after and I knew the discard was on its way...
On the Friday morning he text to say he was really ill and could he come and sleep at mine. I was worried and said yes. He turned up 10 mins later and was a state. He was hungover not ill and had been down the night before to get trashed and not told me he was down.
I barely spoke to him and went to work. When I got back he wasn't in, text me to say he was at the pub and was clearly drunk again.
He rolled up at my door an hour later and I STUPIDLY let him in and furthermore even allowed him into my bed. That night I lay next to him and cried myself to sleep.
He left the next morning instead of staying the weekend.
Again, barely heard from him the next week. I text him and got the response I expected. He wanted to end things.
I spent Christmas in turmoil. I was left devastated again.
A few weeks later he came crawling again but this time he didn't ask to get back together, no this time he was changing the dynamics. He wanted to be "friends". I was scared to let him go out of my life completely and went along with it, basically being downgraded to just a booty call. No more weekends together, we didn't even go out together anymore. I was just there for sex and then he was off again.
I started to reach my limit with it. I was feeling soul destroyed. I still loved him but felt so abused.
My brother took me to the side and told me that he had proof that whilst we were together he had been unfaithful (I had suspected but was never 100% sure)
I was so angry and embarrassed. I called him out on it and he denied as I had predicted, said I was crazy and he was sick of me listening to these gossips. Then told me it was best if we cut ties for good. I was "obviously not moving on" - what a joke, any time I tried to he hated it and came crawling back! I was so angry I didn't care, I let him have it and told him everything I thought about him.
The next time I heard from him he said he was coming for his things. By this stage I had calmed down and was starting to panic. I begged him like a fool. He didn't respond after that and didn't turn up on the agreed day for his things. Another 3 weeks passed. Another text, this time he was trying to be nice, asking how I am, could he come down at the weekend for a cup of tea(!) and his stuff. I said ok and yet again he didn't show! That was this weekend just gone and I've heard nothing more.
I'm so confused right now, I don't know what his game is and I don't know what to do about it.
I know I should tell him to come and get it or its gets chucked but I'm scared. Scared of finally letting go.
I still feel completely rejected and its destroying me that he no longer wants me. I know I sound stupid but I can't help it. The thought of him replacing me, which I suspect has already happened, is cutting me up. He's done and said unforgivable things so WHY THE HELL do I still feel like this?!
I'm so sorry for the long rant, I just needed to get it all out. My friends and family don't want to know anymore and I've got no one to talk to.