How do i get the sensation like i can't keep my eyes open so

How do I get the sensation like I can't keep my eyes open so I can fall asleep? I had it a week ago for the first time in years and I actually fell asleep and stayed asleep but now it's gone. I don't get the falling asleep feeling I sit and wait for 6-8 hours then fall asleep at 7am.. that's not ideal.

You know that feeling you can't keep your eyes open and you'll fall asleep if you close them? I need it back I finally had it and now it's gone I tried for years to get over my insomnia and I was almost there