To short please help

Random bag seeds are never a good idea, unknown genetics, often inbred and likely from hermies and to be hermies themselves. Topping causes a shock to the plant, meaning little to no growth for 5-10 days afterwards is not uncommon. Defoliation will further slow growth by reducing a plants ability to make energy, especially on small plants. Go easy on the ferts, baby plants need baby feeding. 18/6 is all that is required, 19/5 won't achieve anything much extra. A pH in soil around 6.5 - 6.8 is slightly more cannabis friendly. Since it is not an autoflower, you can veg the plant as long as you want before flipping to 12/12 to cause flowering, maxamizing yield that way anyhow.