Oh hun...do you think maybe it is because your DH has gone? He is sprobably missing him and cant deal wiht it emotionally...their little brains arent developed to deal wiht stuff like that yet....20mins out of your night is no big deal when it comes to getting him to sleep happy and safe so keep doing that....would you consider co sleeping wiht him till he feels confident to go back to his own bed..that will eliminate you sleeping on the floor and you will both probably sleep better ?
I do the night stuff alone as DH is a baker so I know how you can get so emotional when your triying to sleep! Your doing a great job, just remember he will only need you to help him to sleep for a little while and you will be happy knowing he is happy Good luck xxx