I really don't think your computer is strong enough. But in case I'm wrong:
Increase your downscale to decrease your resolution as much as it allows (Settings > Video > Resolution Downscale).
Decrease your fps further to 15 (Settings > Video > FPS).
Set your preset to UltraFast (Settings > Advanced > x264 CPU Preset).
Run it this way for 5 minutes and post a new log file from that attempt.
I'm not sure your video card supports Direct X 10 which is required for OBS, by the way.
What kind of computer do you have and who are you streaming to, by the way?
Edit: Unfortunately, your video chipset doesn't support Direct X 10:
NVIDIA GeForce 6150SE nForce 430
http://www.nvidia.com/object/mobo_gpu_tech_specs.html
So I don't believe you can run OBS.