Can I save my cannabis plants?

It was a rough winter for my #cannabis garden. I have a greenhouse that is falling apart. There were several holes that formed in the plastic during cold temperatures. My weather, like many people, doesn't warm past the frost temp. until later in the springtime: Therefore, I have a greenhouse to increase the grow time of my seedlings. Unfortunately, my plants had a bit of frost shock and weren't looking great. By the time I transplanted them into the ground, they were looking sickly.

The plants are looking droopy, they have a yellow hue and they have small dots from malnutrition. I was worried the plants would completely die, or at least become stunted or sickly and underproduce. I started doing research on transplant shock and how other people deal with this problem. I came up with several solutions: Bone Meal, Epsom Salt and Kelp.

The first thing I did was pour Kelp and Bone Meal around the sicky plants and spread them around. I also poured a small amount in each potted plant that hasn't been transplanted yet. Next, I soaked Epsom Salt into a 5 gallon bucket and poured it around the roots of each plant. Finally, I placed kelp into a mason jar of water to soak for 3 days. I plan to use foliar spray of both Epsom Salt and Kelp.

A foliar spray simply means that you soak some type of substance in water and then spray it directly onto the plant. People often do this with compost tea, but there are lots of types, usually it's for nutrients, but it can also be used with pesticides etc. First I am going to do a spray of Kelp meal, which takes three days of soaking, then I'm going to wait at least a day and spray the plants with epsom salt in water. Epsom salt is magnesium, a common plant deficiency.

Last night, the Kelp foliar spray was ready. Above is one of the unhealthiest plant. Notice how the bottom leaves are more yellow, which is a natural defense system where unhealthy plants eat nutrients from the bottom up. All of the plants will probably survive, but some of them might end up being effected full time. I am sharing my mistakes in case they do bounce back fully. Then people can know what to do when they get transplant shock. I am curious: If you are reading this ...
What nutrients do you use in general?
What node do you first transplant cannabis. 5th node? etc.
Have you ever had transplant shock from unhealthy plants?
How did you deal with the problem?
Do you use foliar spray on your plants?
Tonight, I sprayed the dying plants with Epsom Salt foliar spray. It should help "green up" things. I will update everyone in a week or so and see if the transplant shock remedies worked! Also, I found some seeds in case the plants don't do well. They are regular seeds, so I will have to kill half of them. I am a bit worried because the temperatures are reaching +80 degrees F soon, so I will have to keep them in the shade and hope for the best. I think they will be fine though. Wish me luck!