Plants are turning yellow and dry

yellowing at the bottom nodes moving upwards is low nitrogen or locked out nitrogen but i doubt that's the case. I think your intuition of over watering is correct. give it some time and consistency should bounce back.

Drained holes, but I'm wondering if there is a drainage problem here and the wholes where to small.

Nitrogen deficiency bro. Make sure there is drainage holes in those cups. Good luck bro

Your first two photos look like a nutrition issue, possibly nitrogen. First, make sure your pH is correct then review your nutrient levels. The next photos in soil make me think you could be slightly over watering. Do you have drain holes in the bottom of your cups?