Your CYA may not have changed. I'm assuming these are pool store readings. That test is so subjective that there is no way distinguish 80 from 84 and even 80 to 90. It is very subjective. In actuality, your CYA is probably just the same as it was 10 days ago. The only way to lower it is to replace water. Same with your alk reading -- there is no way to distinguish 215 from 211.

I think your volume is probably a little more than 10K. My 24'AG is around 12,500.

You are right that your shock level is around 20. So, raise it on up! And, try and keep it there. Like I said above, every time you test, raise it back up. No such thing as testing too often when your pool is brown/green.

What is your pH? You are adding Borax which raises pH and Lo 'n Slow which decreases pH. Not a good plan.

Tomorrow? More bleach as often as you can. Back up to 20 or so! More bleach!!! Can't comment on whether you need more Borax until you report your pH reading.

Don't be embarrassed. We all have to learn how to manage our pools. It takes some time but you're doing fine.

More bleach!! Keep it at shock level and run the pump 24/7 cleaning the filter as needed!