I had the same issue. My session would freeze up within 2 minutes, in the menu or game. After searching through various forums, there were two things in common for a lot of the crashes: GPU Clock Speeds and DX11. One of the common factors was people using factory (or non factory) overclocked video cards; my video card came factory overclocked. After people reported down-clocking their GPU core, memory and shader speeds down to the reference stock speeds of their card type, they were able to play the game with no further crashing (unless they ran into DX11 crash as well). So, I down-clocked my video card to the reference specs of my model: GTX 560TI (822 Core, 1645 Shader, and 2000 memory), and I was then able to play the game a little longer, roughly 20 minutes, before it would crash.
Then, from event viewer, I found out the dx11 game file was crashing on me. So, I changed the direct x to DX 9 in the game menu. I am now able to enjoy the game with no more crashing! So far, I logged in 7 hours of SP and MP

I wish I would be able to use DX11, but I am just happy I get to FINALLY enjoy the game!
Out of all my games, this one has caused me the most grief.
Good luck!