You're having many lost frames (34%) while encoding 60 fps with x264. It takes the CPU longer than 16.6ms to encode a frame. Switch to NVENC as encoder to be able to encode with 60 fps.
The whole log shows a tendency that your CPU and GPU is almost fully loaded, and the encoding pushes it over the edge. Limit the fps of your game to 60 by activating vsync and/or a fps limiter to keep the usage down. This will give OBS the required processing power from CPU and GPU. If you don't limit your game, the game consumes it alone and OBS starves.
And you have a small amount of lost frames due to network bandwidth or stalls. This is a network problem. To handle this, see this guide:
https://obsproject.com/wiki/Dropped-Frames-and-General-Connection-Issues