Take your chlorine level up to 15 and try and hold it there without letting it yo-yo up and down. Test your water 2 or better yet, 3 times per day, and each time, add enough chlorine to raise the cl back up to 15. Also continue brushing the pool and run your pump 24/7 while you are trying to clear this up.

By the way, what type of chlorine are you using? Your cya is currently at 40 which in my opinion is perfect and you don't need any more. Trichlor or dichlor both are stabilized and will cause your cya to continue to go higher which you don't want. Also, trichlor in particular is very acidic and will drop your pH. 7.3 is fine but on the low end of where you want it.

Can you also post a calcium hardness reading?