OMG first of all if that plant was indoors, the pot is way too big, it should be in 7-11L to make good use of the space.
I think you should check out some tutorials, or look at several diaries on the web, to see where you might have gone wrong. To check measurements, quantities, climate control, some basic things so you can compare.
Then buy some basic nutrients, even if it's just the basics, rooting agent and 2 bottles for fattening and enhancing flavor.
I also recommend looking into some LEDs, you don't have to invest a lot of money, in the end, there are cheap LEDs with 150/200w that can give you 200/250 gs.
If you put in the effort, do it right, cheers and happy growing!