Try meditation before sleeping. It doesn't have to be for a while or very in depth, just keep yourself calm and try not to move at all. Clear your mind and just sit there for a bit. If you do this before you sleep it should help with relaxing both when you fall asleep and when you wake up during the night.

One other thing you could try is using MILD to tell yourself that you won't move at all when you wake up. I used a similar technique when training myself to recognize when a regular dream is fading and now DEILD is one of my main methods. All you do is, while falling asleep, tell yourself, "I will remain motionless while preforming a DEILD" or anything like that over and over while you fall asleep. You can also do this while actually preforming your DEILD though it will take up some of your concentration and make actually preforming it more difficult. It's still worth a shot though.