Your fertilizer is too weak in N. That is a bloom fertilizer. The reason the plant got worse after the flush was because you leeched what N was in the soil, out. I don't think it is PH lock out or salt lock out because you flushed 4 days ago...
Here would be my plan of action...
Stop watering every other day. The soil is good for retaining water for several days. Let the pot dry out once and then lift it with both hands and memorize that weight. Never water again until the pot is that light again. You can also get a long two prong moisture meter from Lowes Garden Center.
Transplant. The soil has been leached of it's nutrients and the roots are likely near bound at this time. I'm fairly confident you have not re-potted recently, because those leaves are crying out for Nitrogen. New MG soil would have cured that. Bigger room for roots means bigger yield.
Replace Nutrient? Get a more complete plant food with a higher amount of N in it. What you are using is a good ratio for flowering or ripening. I even add a small dose of extra N in my grows about 2-3 weeks into flower because the plant uses a lot of it.