is it too late to fix this? (brown leaves)

ok here's the story i got plant food that i used and to was way too heavy so i got nitrogen abundence so i flushed it with a quarter gallon and it got water stress so i am having to clip leaves off with the nitrogen toxicity and and it started going bad because more leave were getting it so i took the plant out and mixed it with dryer potting soil and the leaves are turning brown and dieing

PICTURES:

Flush again with Hydrogen Peroxide; 1 oz added to 1 gallon of water. (3% H2O2). Be patient. Wait one week, do not do anything else. When you flush make sure you have 20% run off. The H2O2 will put O2 in the soil and roots, and will kill any root problems. 1/4 gallon is not a flush.