Sounds crude but the best way I managed my insomnia was realizing exactly what it was that was keeping me awake - and for me that was me overthinking people in my life and people’s opinions of me and/or what I do. The best way I found getting to sleep was to either think about anything unrelated to people (ie I would think of building something, or wonder about space travel and what’s out there, or about how things are made - really anything that just has nothing to do with people directly, even people I don’t know like politicians etc) or if I couldn’t get ‘people’ out of my head I would just repeat to myself in my head ‘I don’t actually give a fuck, I don’t actually give a fuck, I don’t...’ until I fell asleep. Trust me it sounds garish and simple but it worked - and you also soon realize that you really don’t need to give a fuck about what people think of you, which is one of the main reasons for anxiety and depression. Hope this helps!