I like WS4SB and the template Defranco has that you are using is fine. It is not that the exercises you picked are bad in their own right either...You are missing half your lower body work on BOTH days. You ignored a hamstring/p-chain movement on your ME lower day, which is not acceptable, and you substituted it with calf raises (not acceptable and nowhere near enough systemic stress). You ignored a unilateral leg movement and a hip extension movement on your dynamic lower body day. That's half your workload. Even with back pain you should be able to do hamstring, hip extension, and unilateral leg work if you have kept your squats in. And if you decided to take the squats out (which you didn't, and shouldn't if you can still work on them), then the other stuff becomes even more important.
And as Carnage noted, hill sprints and heavy carries are terrible choices for fasted cardio. You need fuel for those intense sessions. Fasted cardio by definition is slow, steady paced, and easy on the muscles. Unless you want to lose some muscle mass and drain yourself. That's why fasted cardio is jogging, biking, hiking, stuff like that.
Also, sports is not lower body work. It is fun, good workout, and great keeping bodyfat low for the casual person, but not a squat workout. Nowhere near the stress needed to grow serious muscle.
Add the work back in. Also I would drop the reps on your shrugs to 8-10.