Nitrogen Deficency! Early Flowering!

well basically im using canna terra soil and terra flores to grow my auto flower, blue mystic. shes under a 400w my temps arent great because its in my attic and it gets HOT! but yeah basically i know its a nitrogen deficency because i diddnt buy the veg part nutes. so my question is

WHAT CAN I DO!??! here are the pics.....
btw i havent really got a clue how old this plant is but its early-ish flowering and this yellowing of leaves has ben happening for some time and now is quite severe, the first picture is the leaves i removed

what can you do go get some nitrogen at a hydro shop or walmart

Yeah man i guessed that much but the thing is my flores nutes have nitro with a npk of 2-2-4 and it seems late to buy nitro rich nutes now (veg nutes)

Better late than never, they will use N during the stretch. edit: Sorry, I have no knowlegde regarding auto-flowering seeds.

i will be buying the veg nutes, as autos do stretch also however i feel like the stretch has stopped so i dno if there is any need anymore or will the lack of nitrogen need to still be compensated for?