Bit different situation - I coslept with DS on a mattress on the floor for ages. Ocasionally he'd have good patches and I could leave him, then finally after he was 19 months or so he entered a longish good patch and that was that (aside from when he was sick or something). So all we had to do was wait. Then after a few months we switched him to a bed.
A seperate sleeping space in your room - floor or cot - might be a good way to start.