A friend sent me the episode Breakup Bootcamp of the Girls Gotta Eat podcast recently saying it resonated with her: https://www.girlsgottaeatpodcast.com/listen. They talk about a lot of this stuff, like the science behind why we feel what we do after break-ups and what healthy vs. unhealthy love looks like.
This is not a binary choice: date him or not date him. The other option is to be single and get your bearings back for yourself. Being single is not some barren island you are banished to. For some its a happy and preferred state. Just a thought.