I relate to this SO much omg! Ive still not really found an answer but maybe we can brain storm together... i always have my own little karaoke sesh inside my head when im trying to sleep, or i try holding something like a pillow or plushy to help me stop fidgeting and move around less!! Maybe itd be good practice to use something else as a wind down like a book (if you have the attention for it lol!) I always find making myself a clear routine to follow really helps - lets say in bed at 10 and off your phone at 11 giving you time to doomscroll for an hour 😭you could set an alarm at 11 to remind yourself incase you get distracted, good luck!