ideas or encouragement welcome

[*Efjay*]

First of all I just wanted to say 11kg @ 7 months!! Thats some good booby juice you have happening there!

I second what Spring said. You don't sound keen on controlled crying. I would be tempted to kick DP our of the big bed if he is concerned about having DS in the bed with you.
Has Ds always been difficult to sleep?
Has anything changed that may be effecting his sleep, if this is new? Like introduction of solids maybe?
Around 8ish months I think its pretty common for babies to become rather clingy which may explain why he sleeps best with you. Or maybe teeth??

Best I can suggest is if you are comfy doing so, try co-sleeping.

Best of luck. I know its hard.

eta - Ok, fair enough about DP's back. Good on you for getting another bed.
IMO, you are right, you have built a trust that you will be there for DS when he cries. I personally think that yes letting him cry it out may break that. But I have never done CC so I can't say for sure. But honestly if its not sitting well with you, don't fo it. But I do think you should go along to the sleep school thing BUT BE FIRM about what you do & don't feel comfortable doing. If its not what you want just leave.

Could you try Popping him in bed with you & just laying with him, jiggle the bed or even him IFYKWIM, like gently jiggle his leg or something so he can feel your there but your not having to hold him. I still can't get over how heavy he is LOL.
Being persistent is the key to success so even though it may take a week (or even more) he should learn that this is the new way we go to sleep. You are still with him, you are still comforting him but this is the way we now go to sleep. No more jiggling.
I think there is a difference between leaving the room & letting him cry to if you are with him while he gets use to the new way. Sure he may get upset about it & kick up a stink, but you are there with him, comforting him & letting him know its ok.
One thing I use to do with my oldest was to talk or sing to him really softly so he had to be quiet to hear me. In my head it helped keep me sane & not scream when he just wouldn't settle. Find a little song that you can just repeat over & over. I use to do the ABC's & twinkle litttle star.

ANother thing that may be a little out there for you but I i will share anyway.. I use to picture (still do at times) a big blue circle that would surround DS. This circle of blue was full of comfort & sleep. Its just something to focus on when they are really doing your head in KWIM. Also I would leave an my energy with him if I was getting up after he was down. I would picture a ball of energy forming in my hands & then leave that by his side. So he could still feel I was there.

Day sleeps, well these are always hard. But if you keep things simple & quiet he will also learn. With him falling off the bed. Its bound to happen. Sorry but it will. You will feel bad & he will cry but I think its just one of those things that happens. All of mine have fell out of bed at some point. The very first time it happened I was a mess!
But you can teach him now (well start to) how to get off the bed. Show him how to slide off on his belly feet first. You will be surprised how fast they get the hang of it.

OK, well you have probably replied to my post while I have been editing it so I will leave it there & add more as I think of it later.