ASMR videos often help me calm down and fall asleep. Many different kinds out there, from soft whispers with positive reinforcement to simple stuff like rain. Just make sure to listen to the audio only, the blue light of most tablet/smartphone screens are really bad for trying to sleep (just like most monitors) because it's a light frequency that keeps the brain awake.
A good workout, like running, can lift the spirits and if you power your body out it often helps to calm down and fall asleep easier. Once you get into regular running it's also a great way to "declutter" your brain from whatever thoughts you might have collected during the day.
You could also try Indica Cannabis, which is usually a good sedative. Tho it can make depressions worse due to the sedative effect, so try with some caution.
Also i usually recommend sativa and to stay away from indica. Sativa turns my depression into productivity, indica into a careless couch potato (which may is what you want tho)
That's why I'm not sure they are that good of a choice for dealing with insomnia, a hybrid might be a good middle ground between light couchlock and lifting mood.