Thing is, you've gone from one extreme to the next. Where is the middle ground that most bodybuilders do? E.g. 6-15 reps per set?
You've done a pretty decent low rep routine whereby it's necessary to "pull back"/reduce stress relatively frequently (typically every 2-4 weeks)...to a routine where you are simply active recovering/pumping the muscles. Those workouts pull more blood/volume into the muscle, and you are probably simply rebounding from your lower rep training - this is where your "gains" are coming from, but they will slow down within several weeks.
You probably didn't do enough deloads/lighter training with the low rep training, THAT'S why you feel better now with the high rep training. As soon as your system has recharged, you wouldn't feel like crap and find it hard to sleep.
Also, your big lift volume/workout was pretty high, most bodybuilders only do one (maybe two) big lift/s per workout, followed by a few "smaller" multi-joint lifts. Most people would feel drained doing all those lifts (especially the power clean). Split your routines up more (e.g. legs/push/pull done 5-6 times a week) and don't do exercises that over-lap so much.
You don't need to go to failure with low rep training, in fact, do this too often and it'l hold you back...so what you were doing was fine (as long as you did some sort of "light"/low volume training to rebound). But with medium to high rep training, you need to go to failure (or very close) to get a good growth stimulus.
This isn't complicated, do a medium rep range, and your training "cycles" will last longer (muscles will get more stimulus compared to systematic fatigue). If you insist on doing low rep training, then de-load often enough (like every 2-3 weeks) or break it up with high rep training.
If you insist on doing really high rep training like 20-30 reps/set (pointless in my opinion...unless it's one rest pause style set like widow maker squats/kroc rows), then only do it once/twice a week as a means of active recovery (to recharge CNS), not to stimulate growth.
All this is pretty pointless in my opinion though, if you stick to a 6-15 rep range then you won't need to worry about "burn out" (apart from the odd pulling back/autoregulation when not feeling great).