Additional Software in Lubuntu 18.04 LTS wont let me install proprietary drivers

So I previously posted about issues with my GTX 570 crashing when playing Team Fortress 2 using the 390 drivers and the drivers tab of additional software not letting me install proprietary driver 340. So I switched to Xorg and tested Team Fortress 2 Mann Versus Machine Again, and while it did not crash immediately, it got 1/3 frame rate of 390 drivers before they would crash and eventually the Xorg driver froze up the game as robots started to come in. Now it weot let me install proprietary drivers saying nothing after applying changes. Im going to restart and try again, but If this is still up or I havent closed this myself, the issue has not been resolve.

A restart fixed this, when I restarted 390.48 was the driver installed. Ive never been so happy to have a defective and problematic graphics driver before. Ill see if this method will allow me to get and test 340. Im hoping and praying to RNGesus that 340 wont crash on TF2 and will still work with Terraria and wont shoot performance in the Knee.