Maybe off-topic, but my advice would be: if you need this guide, consider to switch to another language, if that's possible. In our company we switched to Go, and all those asyncio problems were magically solved.
pull the rows from postgres that match query <x>. Process the data and push each row as an event into rabbitmq. In <200 lines of code i was easily processing 25k/rows per second and it only took me a few minutes to figure out the script.