Your post has got to me in a way that nothing on here has done before as it was like reading my own words from 10 years ago.
10 years ago I fell in love with someone, but he didn't feel the same as me. He was in the process of getting divorced from his 'psycho' ex. I wanted to go out with him and he knew it, but was up front with me saying that he didn't want a relationship, as he was getting over his ex.
That didn't stop him cuddling up with me, sleeping with me or letting me buy things for him. Oh no.
I fooled myself for nearly two years that something could happen between us - after all if he was sleeping with me and being with me all of the time it had to mean something.
He would do the same as the target of your affection. We'd cuddle, sleep together and the next day he would distance himself as far as he could, knowing that I would let him get away with it.
Sadly, it all came crashing down around my ears when we went for a night out at a club, he pulled and brought her back to the house that night and slept with her in the bed we usually shared, while I had to listen to it from my room.
I was a "psycho" for being upset and he treated me like shit until I moved out. She them moved in and they are now married with children.
Nothing has ever hurt me as much as that, but then the hurt turned to feeling like a completed idiot and I would end up going over and over in my head about how stupid I had been. It took me the best part of 10 years and a good year of counselling until I could forgive myself for being such a mug.
Move out. Or if its his flat, get him to move out. You need to get over him and deal with how you are feeling and that won't happen when you are in the same place with him every day, playing at being a couple.
You will never meet someone who will feel the same way about you if you are with someone who doesn't as you will appear off-limits.
Who knows - maybe if you move out and make yourself unavailable, he will suddenly realise what he's missing, but I seriously doubt it. Its more likely that he will move on. So should you.
I can't stop you from making the same mistakes as I did, but I really hope that you take this on board and save yourself the heartache as it will be much worse if you carry on like this until he finds someone else.