So couple of questions.
How does you water look? Cloudy, pretty clear, crystal clear?
It seems with you adding as much FC as you have over the past few days, you should be higher than .5 on the FC part. Something might be consuming it.
I'm surprised some of the others haven't recommended a SLAM yet. I would at least do an OCLT to make sure you are good on that part.
If your water isn't crystal clear but you are passing the OCLT and still have a CC of .5 then your filter might not be doing its job. When you get your new filter, it should help.
I would get your CYA up a little to at least 30 if not 35. Keep your FC above 2 at the ABSOLUTE minimum. I'd shoot to keep it at 4. pH needs to be at ~7.5.
But I think there is something going on with your pool. I still think your FC should have been higher. You were at .5 on your first post. Then you added a gallon of 12%. And you added another 40oz the next day. Then you tested again and were at .5 that time too. Something doesn't look right.
Hopefully some of the more experienced ppl will chime in. I want to see the finished product. I'm interested in your journey......
Oh yeah.....They love pics here. The more the merrier.
From a fellow WV to another......Stick with it.