Get on a good program. If you want a body part split, look into KingofBeef's "Do this Routine instead of that Dumb one" (and nothing personal, but take the title to heart). The fact that you say you "train for size not strength" shows that you really have no idea what you're talking about.
Another thing to realize is that your lifts, despite 4 years of lifting, are still in noob territory. I say that because owning it will help you to just consider yourself to be starting from scratch. I squat and deadlift more than you, and I've only been doing those lifts for just over 10 weeks. And as I said earlier, I'm still a noob and weak as sh**. I say this not to brag or to make you feel badly, but just as a way of saying that you should reexamine what you're doing in the weight room.
The fact that you just casually say 4000 calories without any macro breakdown or specific foods suggests that your diet probably sucks. Look into this also. 4k calories is probably too few anyway if you're that big and really training hard. On a related note, I'd doubt you're "burning too many calories" or whatever.
Again, supps are going to do about 3% of the work.
Eat a lot. Sleep well. Lift your balls off using a sensible program. Come back in a few months.