
Maybe try cutting your volume down in half and see how you respond both mentally and physically!!! Mabe try one set (lighter weight) in the 10-12 rep range, and then one all out set (heavier weight) in the 6-8 rep range!!! That limits all the sets in between and puts less stres on your joints, just an idea!!!
See HIT believes why do more sets than you have to, If you can do 5 sets of 5, then you must not be taxing your muscles as much with those un-necessary sets as you would with 1 set to warm up (higher reps) and then 1 ALL out set of the Heavier weight for 6-8 reps!!!
Example instead of this:
1 set 100x5
2nd set 105x5
3rd set 110x5
4th set 115x5
why not this,
1 set 80x10-12
2nd set 120x6-8
Because without all those sets, you can actually lift more because your muscle is fresh!!! (do I make sense?)