I see from the threads you are at this for 2 weeks, so I can well imagine your frustration level must be way up there.

Problems are, Pool is still green, PH will not lower and Filter pressure too high.

Pool green, from Algae or Copper ?
Googling found this info – The best way to deal with copper is with a chelating agent, not a sequestering agent. The copper products used, as swimming pool algaecides, are typically in a chelated (stabilized) form.
This leads me to think that the Copper Algaecide should not turn the pool green, but if you think it has, you would want to add a “chelating agent” . From what I read, chelation stablizes the copper and keeps it in solution, stopping the pool being green. But only by replacing the water will the copper actually be removed from the pool

Ph will not lower-
The whole aeration process seems simple. Use Acid to maintain lower PH to 6.8-7.0 and then use aeration to lower Alkalinity.
But I seem to recall reading in the forum that using aeration above 7.0–7.2 will increase PH. I may be mistaken on that, I am sure someone will chime in should that be incorrect. But I am wondering if your aerating is actually keeping the PH high. Perhaps you need to stop aerating for now, and keep adding acid, until PH drops to 7.0

Filter Pressure high–
I think that is for the Pool guys who really know the equipment. But I believe it is low pressure means problem before the pump, and high pressure means problem after pump.

I’m also wondering what you have coming out of the filter when you backwash?

Best of luck, we are all rooting for you !!
.