Cold shower really helps me, Cold temperature makes you sleep faster. Also having a fan next to you with air does wonders with pure darkness. If your stomach hurts try drinking some tea and rubbing your belly softly, putting a blanket over you and then see if that helps too.
You have to get a bluelight filter on your screens.
Basically, when you look at your screen, you see and take in blue light, which your brain instinctively tells itself that there's daylight and you need to stay awake. After you've been staring at your screen for an extended period of time, it's super hard to sleep. You can get apps in the appstore that filter out bluelight.
Make sure you had a busy/productive day so that when you put your head on the pillow you can't help but sleep.
if you did have a busy tiring day and yet you still can't sleep then try decaffeinated teas and breath in and out, think of relaxing and nice things you enjoy and close your eyes.
