There is no shame in learning, I do it every day, and we have all been there and have all had our failures.
I would do two things at this point, trusting that they are as bad as you say they are, and please, no embarrassing pictures are necessary. First, grab some clones. No sense totally wasting all this time. Second, try to save these, and see who looks best at the end, the clones ready to go into flower, or these now much bigger and hopefully much improved "slow starters." I am of the belief that practically anything short of death in veg can be recovered from, given the proper environment, and all you lose is time. Veg is the time to build up and survive whatever befalls them, and these weeds are good at it.
My Dad and I are in a discussion about what to do about your roots, and it follows some other recent discussions we have had in this regard. We have been discussing shock.
I myself believed that it was not possible to shock this weed "if a transplant was done correctly" and this was part of my dislike of the belief in the Auto world to NOT transplant. My father as always is an eye opener when it comes to this master gardener stuff and he said that of course you want to shock the plant a bit when you transplant! Excuse me?
Yes, it is possible to mold a hole in new soil exactly the shape of the last container and transplant with absolutely no shock. Yay me. Was it best for the plant? It turns out that it is not.
A plant treated in such a gentile manner will eventually figure it out, but it will take its time and meander the roots down and out into the new soil. Another house mystery has been solved, as to why the plants that my Dad transplanted for me one time were so damned vigorous. It has been gnawing on me, and it seemed upon interrogation that he spiked and layered just like I do... why was that grow so spectacular??
He pulls the roots apart a bit before planting it again! He tries to send them in at least in the 5 directions (my grandpa), and especially if the roots are wrapped, he cuts them!!
Egads.
Regarding your rotted roots, he said
get that shit out of there. Don't be nice. Break those roots apart. (His words)
So we have been talking about me trying this on this grow to see how it goes. I intend to shock my plants just a bit on each transplant. This apparently will cause the roots to go crazy (think pruning) and they will very rapidly fill out to fill the new space, sort of in damage control mode. The resulting "shock" that we see, is like the coiling of a spring... the plant is changing its prime directive while it gets ready to leap into recovery mode.
Hmmm... old people. You really got to listen to them.