Have you tried doing a deload week? Also, have you tried taking maybe about 90% of what your working with and working back up? Basically, taking 2 steps forward, then one step back, then take 2 more steps.
I'm not saying the advice you've already received is bad, it's just I would do the simplest possible fixes before moving on to anything more advanced. There's a lot less spinning your wheels this way and you'll get a better feel for what does and doesn't work for you in the long term too.
I know more advanced training methods sound cool, but they're really not. It just means it takes more time and more thought and even more effort to progress.
If you bring your car to the mechanic because it's making a weird sound, there could be a lot of things that might make that sound. The mechanic will look into the simplest and most common issues before moving onto more complex issues that could be the problem. Troubleshooting lifting issues is like that too.
If you're just getting bored to tears, you could try a program with variety like Defranco's Westside for Skinny Bastards program. Granted, if the PL lifts are your priority, you'll want to stick to variations very close to the comp lifts. Like changing your bar position on squats or your grip width for bench.