Hi S.!
I think you're doing a great job, and if I were you, I would just continue what you're doing :o)
The wonderful part is.....your son is learning to sleep in his bed, even if he is uncomfortable. He's learning that mommy & daddy will be there for him IN HIS ROOM when he needs you.
Just be patient with him. Kids go through so many different sleep stages for us parents to try to figure out. Your son is probably teething again, and needs more comfort.
Focus on making him comfortable for teething all day~ (you know, cold wash cloths to chew on, etc...), then I would plan on giving him Motrin/Tylenol tonight at bedtime. Your problem sounds as simple as teething :o) however, is not always that "simple" to comfort :o)
I know you're probably not as comfortable sleeping on his floor :o) but it's better than creating the co-sleeping situation (if you're against that).
Sweet Dreams to your family :o)
:o) N.