Yellow and brown color spots and dying leaves

Looking at your previous question about, I'm assuming the same plant, you already got an answer that your pH was too low. Your soil is too acidic. You need to do a full flush. Take her to the bathroom and put her in the tub. Get some distilled water and slowly poor water through her pot...and keep going. You want LOTS of run off. You're essentially rinsing any nutrient salts away and resetting the pH of your soil. After flushing let her soil dry back all the way before watering again. Then give her a compost tea, or if you're lazy like me, get some Terp Tea and make a tea with that. There's tutorials on youtube on heow to make the tea, or you can just follow the directions. That will bring the grow medium back to life. The bacteria and fungus in the tea will help manage the pH in the soil as long as the microorganisms stay healthy. Just make sure that you are pH-ing your water whenever youre feeding or watering, and if you're feeding with synthetics, you're watering to run off every time. Otherwise salts will build back up in the soil and throw your pH off again.