H.M.
we had to put our twin boys (now 2 1/2) in beds (also did mattresses on the floor first) at 18 months. Yep, 18 months because they could get out of the cribs and our pediatrician freaked out because of the danger of them hurting themselves. I took EVERYTHING out of their room except the beds and dresser, tethered the dresser to the wall studs, and only have a lamp and fan (for white noise) pushed all the way against the wall on the dresser.
Then we got one of those "clam shell" thingies for the door knob so they can't open it. Essentially locked in all night unless we opened the door for them.
For the first few weeks, they ran around like wild animals and literally picked up the mattresses and had "pillow fights" with them. We would find them in the morning in all sorts of crazy configurations, at times with one boy sleeping on top of the other! They slept on the floor next to the mattresses, and then on the floor UNDER the bed for a while, too. It was just something they had to get used to. Toddler sized sleep sacks worked well to make sure they were warm since blankets were out of the question.
Is there any way you can close the door and let your son work it out on his own? If he's not scared and just walking around, why can't he just walk around in his room? He'll fall asleep eventually. Remind him before he goes to sleep every night that this is sleeping time and he is to stay in bed and be quiet. I still have to do that! Use a monitor if it makes you feel better (I did-- mounted it to the wall behind the dresser so they couldn't grab at the cord or pull it off the dresser).
I know you're so tired and really need rest, but I think going back to cribs is a bad idea. I would be shocked if your boys weren't too big for the crib tents. God forbid they get hurt falling or getting tangled in the tent. From what you've noted and my own experience, I would say this is just a transition period that you all need to work through.