Apothecary,
I just read this whole thread, every post. I have a strong suspicion that when you did the routine that CT very generously laid out for you, you sacrificed form for weight, and that’s why your lower back started giving you issues. It simply doesn’t make sense. If you can squat X weight with good form and not have issues and then squat X+5 with the same form, you’re not going to have issues simply because it’s 5lb more. You issues are from trying to make too much progress too fast and getting caught up in the numbers.
You are going to keep struggling, and struggling, and struggling…until you can swallow the ego and do EXACTLY what those much stronger than you are telling you to do. Even with 5/3/1, you were adding way too much crap to it because you don’t know what you’re doing. You stated the problem right in your original post- doing 5/3/1 BBB and lost weight- if you are eating enough food to GROW, you will never SHRINK- doesn’t make sense! Therefore, you weren’t eating enough to grow- and that’s not “probably”- it is DEFINITELY. If it were a problem with the program, but you were eating enough to grow, then your bodyweight would have still gone up, just probably not how you would have liked. Hence, PROOF- that you weren’t eating enough as your weight went down. More doesn’t equal better. Most skinny guys (all?) don’t do awesomely with super high volume like you think you need. Much better to hit a few compound moves with lower volume 3x/week, and spend all that extra time you’re not in the gym EATING! What do you know- both 5/3/1 and the plan CT outlined advocate a few compound moves 3-4x/week as the bulk of the program. Maybe they’re onto something?
If I were you I wouldn’t go around speaking about 5/3/1 or this routine CT outlined as you didn’t follow them properly, and therefore really haven’t done them.
Take these words as constructive criticism, or remain skinny and weak- that simple.