Username85. You need a plan.
You got all the ingredients to hand to get a successful grow under yer belt, weather permitting
Your plant food of 2 2 2 with trace elements will do.
Let your plant get on the dry side - the container will feel light when you lift it.
Place container in a drip tray .... if you have one, if not don't worry.
Mix up your feed as per the instructions on bottle and drench the soil, I mean drench it till the water pours out the bottom big time.
This will flush out all the old, stale nutrient and give the roots fresh nutrients to get its teeth into and will help with the slight nutrient deficiencies.
The pot will be super heavy after you do this.
Then leave it for a couple of days until container gets light to lift , damp Not dry and water as normal next go. It'll take 4 - 7 days for feed to kick in and plant should start looking greener and healthier.
As for the 12/12 flowering outside?
Maybe this will shave a week off your finishing time.
Give the plant 12 hrs of light and 12 hours of darkness by covering it with something.
For example your plant is not that big, Sooooo........
Get 3 or 4 bamboo canes, attach them to outside of pot with tape and use this frame to pull over a black plastic bin bag or such to give it 12 hrs of dark at Same Time every evening.
Looks like it'll finish very late October early November frosts permitting.
To help with the colder period, ie frosts, place the plant really close to your house in a south facing area.
Trust me...... I'm a Doctor