If it were mine, having read the above, I'd give it some blood meal tea which is full of good nitrogen and goes to work quick and has less chance of burning because of overdoing it because it's organic. I make it with a tablespoon of blood meal into a gallon of good water and then let it sit for a few days which allows some of it to leach into the water. You can speed the process along by shaking the crap out of it after it's sat in the sunlight a day. Probably get it going even quicker by actually brewing it just like a hot tea. Of course cool it down to luke warm when you give the sick little sucker a drink. They say luke warm water is accepted by the plants root system quicker than cooler temp water.

Just my thoughts and I'm no doubt an expert but have read a lot.