i have almost got an LD doing WILD about 5 times, but every time towards the end, i always HAVE to move, its so uncomfortable, i tried sitting still a couple of times, but its waayy too hard, and it gets really hot, is there anything i can do?! 
before you being, get in a spot you know you won’t move from, and lower the temperature on your air conditioner. Or get a fan (preferably silenced imo) and use that. But don’t lower it to low, because then you’ll feel extremely cold.
Repeat affirmations to yourself. I have a similar problem, but if I find a comfortable position, and I concentrate on my affirmations, it’s so much easier to stay still.
An excerpt from my own sessions would look as follows:
I am completely comfortable and relaxed. With every breath I take, my body falls into a deeper sleep. My body falls asleep while my mind stays awake. I am totally calm, relaxed, and still. All the tension in my body has drained away. I could lie like this forever… etc, etc.
The key is repetition! Work at it until it becomes natural. It’s one of the best ways to keep your body still.
Good luck. 
Lol. If you could still feel your body - you were nowhere near.
Its pretty easy to relax and lie still. The hard part is what to do after. When you lie motionless for 1,5 hour without any progress - it sucks.
I’m in the same place as you, Eldwinn.
my trouble is that i fall asleep at night, but can’t in the morning.
I dan’t be bothered to type it all out, but I have a paradox that means i either get to comfy at some stage in the night and fall off to sleep, and I can’t get to sleep in the mornings because it gets too uncomfortable
what i read about this somewhere is that your brain sends signals your muscles, making them want to move and such, and if you dont move the brain thinks your alseep, and will then start the dreaming process
Now if that is true, then that is VERY useful to know
Yeah, I’ve definitely heard that, too.