USB Loader GX problem with Wii games

I used to have no problems with my USB loader GX before (i can play any games that i have downloaded from the internet) but when i try playing my existing games that i have bought in discs before, my wii disc mounter would first take it in then spit it out halfway then take it in again and completely spits it out that my disc would fall. i think there's probably(?) a problem with the disc mounter after i installed usb loader GX and the D2x-CIos installer.

I tried downloading those same games that i used to have in discs from the internet, i did verify them and there's nothing wrong with it, but whenever i try to play it on my usb loader gx, it would take me back to the Homebrew menu.

Ex. I have the Harry Potter Order of the Phoenix disc game, since my wii won't accept the disc, I have to download that same game from the internet with verification there's nothing wrong with it. But the downloaded game returns me back to the Homebrew menu. I did delete the saved game from my wii's system but the situation didn't change.

Sounds complicated but I really hope there's an answer to what I asked for. Please do help me out. I already did searched Google for similar situations to mine and this now is my only hope :(