How to rescue this plant?

Hi guys,

I harvested an amazing plant last week. 6 foot, 7 colas, lots of fat bud.
I had problems growing initially with bugs due to bad environment and 1 of the 2 plants still hasnt recovered. it's been like it for the last 2 months, regardless of what i do. it's not heat, not too little watering, not excess nutrients, not too little nutrients and i have done a complete flush a couple of times with plain ph'd water.
there's not many crystals on the bud, where as the other was harvest ready.

any tips on how to fix this plant?
it's got alot of flowers on it, but no real leaves and not many trichomes. i'd like to harvest it as soon as possible and just be done with it.