is it too late for my baby to recover?

Here's the run down...
Currently at week 5 of flowering
1st time growing
1 plant - white widow feminized
coco coir medium, general hydroponics nutes kit (florabloom, floragrow, floramicro)
grow box in a closet using 2 CFL's (60W), exhaust fan, and I leave the door open when the light is on if its warm...
I always ph my water and nutes before applying...
last week, the average temp was 75-85 degrees... and I hadn't flushed nutes since beginning flowering stage...
I noticed some yellowing of upper leaves shortly after beginning flowering stage, it has gradually gotten worse over the last 5 weeks, and this last week has been awful

Prior to this week, I was casually trying to keep the heat down, and I moved the lights up a bit (I have been keeping them about 3 inches from the top of the plant, and I did have a third bulb that was on the bottom of the box to fill in some shadowy spots, but I removed the extra light this week)

This week, its like she's taken a nose dive to plant hell No growth in the last week at all... I did trim some leaves last week to allow for more light to get to the buds, but it does seem like since then everything has just gotten worse...

I have found some generic guidelines I have tried to address the issue, but to be honest I really feel like I have reached the point that if someone knowledgeable doesn't guide me with my specific plant, then I'm going to lose her for good and be very very disappointed...

What those guidelines told me, and what i have done - flushed with ph'd water, waited until the top inch was dry, then added nutes at half strength. no improvements, only worse and it has been three days.

so... what do you guys think?

youve flushed youre coco at week 5, that only made things worse, big no plain water through coco,

also what do you mean with this, as i feel you complete smashed youre buffer sysytem if youre coco ,,,,,,,,,,,"and I hadn't flushed nutes since beginning flowering stage...

also what ypoure ph of youre nute/solution's and the what make of nutes you using and how many times a day week you been feeding and have u been feeding plain water in there, are u using calmag

one sec i just seen youre nutes sorry i miised that, yoive been using general hydroponics nute kit in coco

shit
so i shouldn't have flushed? I thought
can I recover? should I add more nutes?
Am I using the wrong nutrient set?

try to put things together, read your plants not posts, if the problem got worse when you cut back your nutrients, its a nutrient problem. If it got worse from lowering strength, that means something was too low at the strength you were using prior to that. I would go back to the strength you were using, and bump it up. Looks like a p deficiency to me http://www.420magazine.com/forums/problems-pests-disease-control/81275-cannabis-plant-pest-problem-solver-pictorial.html If discovered that it truly is a lack of p, get some 0-10-0 or anything thats pure p, and use it at maybe a 10-15 strength. My opinion though, not fact.

thanks guys
I added some nutes this morning as I agree it does look like she needs it...