After sucessful female, Now yellowing lower leaves, purple stems, pics included please help

Hello,
 
After using this forum for help sexing, I have successfully removed a male, and found that my other plant is a delightful female. All seemed to be going well, until the bottom leaves began yellowing, and eventually wilting completely. At first, I thought this was due to the beginning of the real heart of the flowering process, however, the yellowing has continued to crawl its way up the plant and I feel as though my babies may be in danger.
 
Mind you, I am growing in a stealth grow box, built myself, with two lights, and a fan. The temp is always below 80, but never below 70. I only have a certain amount of room to work with, and attempted to flower the plant early, after 2 weeks of veg. I water when the soil is dry, and this is my first grow, completely out of the blue with little to no experience. I was not expecting much, but after 2 months of work, I really would like to make this work.
 
MY question, what is wrong with my plant, and what can I do to improve the quality of life over the next few weeks while it finishing flowering? And also, about how much longer do you think the plant needs until I can harvest? Im okay with a slightly early harvest.
 
I have began to think it was a nitrogen deficiency and ive added dried blood, but saw little improvement from two days ago to today.

 

Thank you all!
 
Almost instantly after your first reply, I carefully removed the male. The other plant eventually showed its sex to be female! I thank you all for your assistance.
 
I have a new post, however, as I am having a little trouble with the lower levels yellowing... Hopefully I can gain some more help from my trusted grasscity users! Thanks again

 

Damn it... Wrong post. Stoner problems. That was meant for my other post about sexing from a few weeks again. Lol....
 
Still could use some help on this one though