Are you stressful? Cus thats a killer. Also exercise in the day so you are more tired. Or try to
How many days have you started LDing? Because (from past experiences) the first days I was sure I was gonna be Lucid. It would take me 2-3 hours to sleep. Then after I noticed I wouldnt get lucid in a while I fell back in my regular pattern Let time do his thing and dont think about becoming lucid while going to sleep cus its gonna take hours and u wont go anywhere.

Also, get in a position ur comfortable. I cant sleep unless im on my stomach, so I do. And I dont get ppl that sleep on their back.