Unless you are using a reverse proxy to provide https, then you can’t do that. You have to have https. And if you remove the lets encrypt you must also remove the https template (whatever it’s called).
I don’t quite understand why you’re getting the redis error; maybe you commented out redis when you commented out lets encrypt? That’s my best guess.
You can try following Setting up Let’s Encrypt with Multiple Domains to add a second domain name, or wait a week.