GTX 570 Problems

OS: Lubuntu 18.04 LTS AMD64
GPU: EVGA GTX 570 1280MB
CPU: Intel Core 2 Quad Q9650 OCed 3.33Ghz
RAM: 2x2GB DDR2 OCed 888Mhz
Motherboard: GA-G31MX-S2
Bios: F4

When I open Team Fortress 2, it would crash almost instantly upon joining a match when I was using my Intel Core 2 Duo E8600 @3.33Ghz. I switcher the other day to a Intel Core 2 Quad Q9650, and at stock clock Team Fortress was stable but would jitter due to the ram being slow, I decided to test Mann Versus Machine, and before even the robots were coming out to attack, it crashed to desktop. Previously it would crash the whole OS so this was an improvement but not being able to play a game was still the end result. I have OCed my cpu in hopes it might change the crashing and of course my mobo OCed the RAM accordingly, which was the real goal. However it instantly crashed. I know all the hardware is more than sufficient for Team Fortress 2, so I dont understand why my GPU keeps crashing. I am pretty sure it is driver issue. Im using 390 proprietary. When I try to select 340 proprietary as another option Lubuntu refuses to even download it saying it doesnt belong to them. Please help me. I just want to play Team Fortress 2. Last note: Terraria works just fine, I havent been able to test minecraft since Lubuntu refuses to let me install it properly.