Source hates me and when it cooperates with me, it doesnt

[Funley]

Either my graphics card (nVidia GTX 670) hates Source or vice versa, because i cant use Directx 9 with any source game. I have to put "-dxlevel 80" to the startup parameters to prevent the game from crashing immediately when starting. After it has started, i have to put "mat_dxlevel 98" to the console so Directx 9 would work which of course requires me to adjust the settings for the game to look good. And even after that, shadows look like shit and using any kind of light crashes the game. Yes, i have updated my graphics drivers three times already. No, i have not tried to download Directx 9 because Google leads me to some odd untrustable sites. This problem is in GMod, GMod 13, TF2 and maybe some other Source games, haven't tried. If there is anything i can do to make Source like my Directx 9, i want to do it. Even using Directx 11 doesn't work.