What's wrong with my plant?

{'m with yan. It has happened to me before when diluting all mix with some generic compost. After a few weeks soil is depleted of the good stuff. I even tried upping feed doses but took a few weeks more until things got back to somewhere healthy. I have repotted a mid flower Auto before because things were so bad and after a week or two it bounced back with a decent harvest but repotting is not adviceable really.. Much bigger pot filled with good substrate should eliminate this prob in future.

your irrigations habits look suspect. 1) fully saturate.. no half assing it. If soilless, also get 10% runoff, religiously. 2) wait for appropriate dryback (or loss of weight or depth of dryness on top) and repeat. you look to be drizzling a little water near the base of the plant because that's the only spot that shows moisture. PRobably got a bunch of dry pockets and more moisture up top training superficial roots etc etc.. all sorts of bad things develop over time when you have poor watering habits. if the soil is as yan402 explains, treat it like soilless, in my opinion. Buy soilless/hydro nutes. Your house also won't smell like shit that way too. Full diet every irrigation with 10% runoff, which will prevent buildup of nutrients in medium.. At that point any symptoms seen are a result of the formula, which makes diagnosis easier, too.