How to fall asleep while going through a breakup?

Pathetic post incoming! Getting kinda desperate here.

My relationship ended a few days ago and during the day I manage to keep myself busy, but at night I can’t shut off my brain. My sleep schedule used to be very stable, always went to bed between 11 and 12 and woke up around 8. After the breakup I usually manage to pass out around 3am but I’m a very vivid dreamer and every dream I get revolves around my ex, causing me to wake up multiple times a night and getting too emotional to fall back asleep.

Any ideas on how to calm my brain before bed and/or how to stop waking up every hour? Thanks everyone ^^