Italy is bugging and crashing

Since the Italy has arrived in the game, I was skeptical about its performance. I was amazed then when I saw that I can run Italy with 3+ cars on full settings. But, things have unfortunately changed. Since 0.16 update I can't play on Italy map, if I don't change all quality options to normal or lower. For example, on WCA when I just change the lighting to lowest and keep everything on full settings I can run normally. Which is not the case on Italy. IDK but it bugs a lot. When I try to spawn a second vehicle or to change the current it simply crashes, even if the lighting is set to lowest. How can I again play Italy normally?
Maybe there's a problem about GPU (I use Nvidia GeForce GTX 750; I thought this is a problem because on recommended settings it says that GTX 780 or equivalent should be used). But, it's strange to me how I could even run Italy smoothly before, even though I had a weaker GPU.
From the rest, I have Intel Core i5 processor, OS is Windows 7 Ultimate and 8 GB of RAM memory.
Thanks in advance.

 

Bugs a lot means that map is virtually unplayable, even when I set quality settings on lowest. For example when I try to simply drive a car, game isn't running smoothly, i.e. it freezes for a few seconds then runs few another seconds, and after that again freezes, and so on. Regarding crashing, when I try to spawn a different car, it crashes with a simple message:"BeamNG has crashed - send error report."

 

What i5?

 

I'll check that. But, also when I first time start the game it lags, when the computer is relatively cold. But, high temperatures are very possible cause. I'll see what's going on with it.

 

i5-4440 @ 3.10 GHz

And here are the temperatures in the morning, when I just started the computer.
Also,there's a log (not sure if it's the right one).