First - uninstall streamelements - just puking all over your logs and I constantly see system with problems having that installed.
To get something stable, start by dropping to 30fps
19:15:45.355: Output 'simple_stream': Number of lagged frames due to rendering lag/stalls: 1428 (65.0%)
And is there a reason you aren't using NVENC with that GPU?
also check you Windows Game settings and implications for streaming/real-time video encoding (lots of Game items listed as On, and usually see recommendations to turn off)
And basic Windows OS hygiene