So for watering, it’s best to wait until the pot is very light, like it filled with styrofoam. Then water/ feed slowly so all the soil gets wet, for a 3 gallon pot it should take about 3/4 gallon for 5 gal pot about 1 gallon. When a plant has been underfed for awhile it sometimes looks worse when you feed it because it starts trying to grow again but hasn’t caught up on all the nutrients yet. It will get over it with a couple feedings. If you were feeding it when the soil was still wet/ moist it just adds to the overwatering and make the nutrients unavailable to the plant causing it to look worse.
My recommendation is to wait for the pot to dry out and give it a good balanced feeding. Until then you can give it a few foliar feedings by mixing up a gallon of regular feed, ph it, add 8-10 drops of liquid soap so the spray doesn’t bead up on the leaves. Spray the leaves well too and bottom. Since you’re in flower try to avoid spraying the buds, a little overspray is fine. When foliar feeding I turn off the lights for an hour or until the leaves are pretty dry to avoid burn
If your plant had too much nutrients, enough to cause burning, it would be dark green with shiny leaves. I can’t see any signs that they’ve ever had too much nutrients .