I would honestly ditch the blankets. If they're blocking windows or whatever, I'd suggest something that won't hold water in it and is reflective. Also, they're a perfect breeding ground for bugs, mold, and other bacteria. I watched all your grow room videos and that's something I noticed. Probably part of why the mold spread to the rest of your plants I'll go back through other posts to see details on the rest and give my thoughts. I just want to double check my information before I offer more advice, I don't want to give any bad information.
Edit: I see you're using Miracle Grow. I would definitely change that for the next grow. If you're going to use Miracle Grow, there's a guy on here who swears by the type designed for tomatoes. That said, there's a lot of good options out there. Do you pH your water every time? You could have a pH issue that's causing nutrient lockout if you don't. Another thing, the standing water being in the trays could have possibly caused root rot. If you have something like Hydroguard, try watering with that for a little while. Wait until the pots are light before you water again, should be a few days in between. They definitely want to keep going, but it's a matter of fixing a few things first. I hate to throw out plants, especially when they get big like that. Hopefully some of that helps.