The nightmare continues

Check this out. Butter wouldn't melt, right? Picture of serenity, huh - little chap all snuggled up in mum and dad's bed.
HA!
The last few days have been nothing short of a nightmare. Oh, hang on, you have to have sleep to have a nightmare so that's not technically possible.
Saturday was the day my tot decided his recent growth spurt made it possible to hitch a leg over the cot rail and climb right on out. He did this when he was supposed to be napping on Saturday. I heard a thud and, assuming he'd bumped his head on the cot, went in to check he was OK.
Only to find him standing at the door.
Right-ho.
So I settled him, read another story, walked out and within two second ... bang. Out again. And, not sure what to do, I put him in our bed, which is when the pic above was taken. That night we approached bedtime with some trepidation. We made a big fuss of putting the mattress from his cot on the floor and he took it in his stride and went to bed fairly happily. Until about 5am, but I guess that's a good effort.
Sunday: no day sleep. Not possible when you're as strung out as he was. Sunday night: the fight goes on. All the books I have say to calmly pop the child back in bed, explain that they need to stay there and leave the room.
Nice in theory.
It's just that our son was beating at the door, calling out "Mummy, where are you?" and CLINGING to my leg when I opened the door (not to mention trying to escape out of it).
So we did get him to sleep by reassuring we were here ... through a shut door and basically having him cry himself to sleep.
Horrible.
Appalling.
Soul destroying.
I worry that I am switching on something in that happy little boy's brain that turn him into a clingy or anxiety-ridden child.
Shaun has been away since Monday and so all the sleep dramas have been left to me alone.
Needless to say, I've not handled things very well.
Monday nap: I actually lay in his cot (which now has one side removed until we get a chance to go and buy a proper bed) while he drifted to sleep.
Not my smartest move.
That night: "Mummy sleep with Ewie". Err. No.
I stayed with him a while but every time I tried to edge out of the room he HOWLED. I'm talking hysterics. So unfortunately I couldn't see any other way to get him to sleep than to have him cry it out.
Meanwhile I sobbed my heart out in the next room.
It is truly taking a toll on me.
At about 2am - thud. He'd rolled out and cried that he had a "sore bacK" so of course I had to let him into my bed. Therefore there was very little sleep at all. For either of us.
The mixed messages I have given him! Poor kid must dread bedtime as much as I do.
So I am exhausted.
No, beyond that.
Beside myself.
What to do?
Today I skipped the day sleep (chicken!) and tonight I made another big fuss of putting the cot mattress in our room. I firmly told him there was no sleeping in our bed but he could sleep next to us. It'll be fun, I said.
"Yes Mummy," he said.
"Night night Mummy," he said.
HA!
I have been through the entire rigmarole again tonight.
Now I have no idea what to do next.
I can't have him in our bed as he's too damn wriggly and he insists on sleeping right up against my face.
We will (have to) get a bed on the weekend but there's a few days between now and then.
Am at wit's end.
Googling the problem is no help. Everything I have read says 'put them calmly back in bed' ... no mention of what to do with a hysterical child that's just about hyperventilating with anxiety.
Fingers crossed we work this out soon because I don't cope at all well on too little sleep.
Right, am off to order a Wiggles doona cover online.
Surely that's gotta help the transition?