changing the photoperiod is always bad!
it often causes your plant to go hermi.

why would you want to have 2 hour dark i your light cycle...
it's a bad idea

putting your plant on 11/13 will make it finish faster but lower the yeild.

you really should be able to find a flowering fert with more phosphorus and less nitrogen. since you havent had one it has probaly reduced you yeild

hope this helps