ETS2 frame issues

[Shake]

I've used to play ETS2 at like 20-30 or even 40 fps a few days ago, but now I barely reach 20.
Is there anyway to config the game so I can reach higher fps? I got everything on low.

Specs of my shitty toaster:
- AMD E1-1200 APU 1.4GHz
- 4,0 GB RAM
- AMD Radeon 7310 HD
- Windows 7 Home Premium 64-bit SP1