Ldywulf, I see a smorgasboard of issues, and I don't think those plants are going to survive. One reason I asked all those questions initially is because I, too, suspected herbicide drift based on your first photos.
But your subsequent photos suggest bacterial and/or fungal diseases and show that you have some sort of caterpillar — those little dark pellets on the second photo above are caterpillar poop.
Overwatering, overcrowding and overfertilizing all weaken a plant and make it susceptible to disorders. The large leaves and spindly stalks say too much nitrogen. If those are Mammoth or similar variety, they are way too close. Fungal and bacterial disease thrive in moist conditions.
If they were mine, I would pull and destroy them (in the trash, not compost) and write it off to a learning experience. If you want to try to save them, pull out every other plant, remove the most infected leaves, and stop watering until the soil dries out at least 2" deep. There are products for both disorders, but since I don't use them I can't recommend any. But really, I don't think they're worth saving.