I have lived on a few hours sleep and up at 3-4am for a few years now
Recently I have had a few months without drinking and this has really helped, I didn’t think it would as occasionally I’d have a beer or gin to help sleep but found I’d wake at 3am

A totally natural thing that has been recommended to people I know and worked really well apparently is tart cherry juice apparently it’s good for quite a few other things too
But I know a few people who absolutely swear by it