Hyundai Aftermarket - I NEED HELP!!!

I am new to this forum so please forgive me for my long-winded description of my issues.

I have a 2001 Tiburon with 255k miles on it. I was stupid one day and filled my tank up with the nozzle facing to the left and destroyed my EVAP system. I had the P0455 code that came up later and I drove with the code for about 9 months just dealing with it being annoying to fill up the tank. The last few weeks in October I began to feel a lot of sluggishness when hitting the gas. It got to the point where acceleration was very difficult and going up hills was a challenge. Over the months I checked the codes and there were never any other codes. The first week in November I decided to knock out a lot of things that I've been neglecting such as tires, suspension, spark plugs, fuel filter. After I did those things, the sluggishness was there and more intense. I decided that I needed to then take care of my EVAP system thinking it was something fuel related. I changed my vent valve, purge valve, canister, fuel tank vent valve, fuel pump and strainer, pcv valve, and every rubber hose and clamp in between. Much to my surprise, after practically putting a new fuel system in my car, it still had the issue. The reason I changed the pcv valve with all of that is because I stumbled upon it leaking oil and my valve cover leaking oil with it. The pcv valve was all clogged up and it probably had been for a while.

Current symptoms are; Engine bogs down when hitting gas - usually all the way down to stalling, White smoke coming from exhaust - doesn't really have a smell, Old spark plugs were burnt to a crisp - they were a year old with 30k on them.

At this point, I don't know what it is and I don't know what to do. Any help would be greatly appreciated!!!