I honestly don't know what's wrong

agree with others. read it and go off that.

Looks very dry and suffering from incorrect watering habits........0011 has given solid advice about watering. 18/6 is optimal, you won't achieve anything extra at 20/4 except a higher electricity bill and a stressed plant! Next time grow photoperiod fems, autos really don't offer anything special and are a lot harder to get to perform, especially for newbies.

0011 describes watering soil perfectly, a lot people don't understand watering cannabis in veg particularly requires drybacks (actually encourages and is required for vigorous growth)

well, sounds like you already know the answer in your question so why are you here? You only got about 1-2 more weeks of stem elongation/leaf growth, if that. So, don't expect much more. Most people have a really weird interpretation of overwatering. 1) saturate entire pot - dry pockets are bad 2) wait for appropriate dryback and repeat. This process cannot cause overwatering. It's easy to follow. If you experience droop after an irrigation that is not overwatering. That is a poorly constituted substrate that needs more perlite or similar. If half-watering or choosing a volume that 'feels' right to you .. or whimsically choosing when to re-irrigate instead of based on weight loss/dryback, then you are doing it wrong, and these behaviours should be amended. 20/4 is not better for the plant unless it's a shit light that is underpowered for the area you are trying to cover. you should shoot for 35-40DLI produced at diode and focused on an appropriately sized area of coverage - this 2nd part mostly has to do with hanging distance.. 18/6 should be plenty. If you are covering a space similarly sized to what the manufacturer recommend for "flower phase" then you should probably reduce to about 67% power over 18 hours. This in part depends on the integrity of the manufacturer's suggestions.