Really low FPS

[Jweezy]

Hey guys i just downloaded the game and did the tutorial. While playing the tutorial i allready had some fps problems around 40 but when i joined the first map my FPS dops to 10-15 on lowest resolution and i dont get why :/ 
I have win 7 Home Premium 64 bit 
Intel (i5) 4210 H @ 2,90GH

8 GB RAM

NVIDIA 950M

someone has the same problem and maybe knows a fix for this? I allready tried updating my Drivers but it also didnt worked.