LT,
The advice given so far about eating and rest is good, but you might also try microloading. 2.5 kg jumps for press and bench might be a bit much. If those things don't work, it may also be time for you to consider going to the advanced novice program, where you only squat heavy twice a week.
Judging by your squat video critiqued by Rip, you need to reset your squat weight and concentrate on depth. I reset about 30kg when I took a video of myself and realised my depth was poor.
Also, in your video, you need to work on your grip. Your hands were way back which will cause severe elbow pain with higher weights.
I agree with your first point.. However reset 30kg is too big IMO.
2nd point I have to disagree with. I actually lifted my elbows up like that because it helps balance the weight better on my traps, I used to have my elbow in line with my torso, and found that the barbell would slip off my back and my wrists would have to support the barbell heavily, I acrtually injured my elbow when I lowered my elbow..
WIth my elbow up high, my hands don't do any work, my traps are more horizontal and support the weight better.
You're asking a question about programming. To me, that implies that it would be helpful to read a book about programming.
You ask if this is indicative of a bad diet, or has to do with your recovery ability. These two concepts are linked. Follow Colliflowers advice. Eat more and sleep more. Maybe start a food journal.
Is it just me or is my SS the only one with a programming chapter at the end? I know it's not as detailed as PP, but i'm pretty sure it still talked about what a reset was.