Can’t help with diet.
Training-wise I’m honestly surprised to hear you burned out doing 5/3/1. Were you doing exactly what Jim says to do? What variant were you doing and for how long? My understanding is that he set 5/3/1 out to be very sustainable for a long time. I wouldn’t think your numbers are too high for SS really, but if that’s the road you’re looking at going down I’d recommend the Texas Method over SS.
That being said, if you found 5/3/1 too heard in terms of volume, the Texas Method mightn’t be your thing either. I’ve head the Texas Method isn’t great for people who don’t recover too well.
Unless I misunderstand what you mean by burned out, that is. Do you mean you got bored? Because if you got bored, I’ve got some bad news for you: the vast majority of people do best hitting those main, basic lifts with a bit of assistance work for a good long time before they need much more variation.
Your numbers are nowhere near high enough that you’d benefit from varying the lifts much as far as I can tell. Add around a couple of hundred pounds to your squat and DL and a hundred pounds to your bench and maybe Westside style training would be good for you simply because of the variations of the lifts they use.
I’m not trying to be a jerk or anything, just being honest based on what I know. I’d really recommend considering doing 5/3/1 again and sticking with it for a good while. Doesn’t Jim say to rotate assistance exercises every four weeks or so? That would give you some variety.