You have some massive encoding lag going on:
10:37:08.275: Video stopped, number of skipped frames due to encoding lag: 68514/90599 (75.6%)
Your rendering lag I would say is highly likely caused by the encoding lag and will most likely clear up by itself once you manage to get the encoding lag under control.
In your logfile I noticed you have Windows GameDVR enabled. This may be a cause of the performance issue as even when you are not using it, just having it enabled in Windows settings it will always hook into the game process and commit resources (Similar to what OBS does when OBS is open, though more aggressively as it also buffers for replay recording)
Your scene 'ROBLOX Channel' has both Game and Monitor Capture.
You should remove the monitor capture source from this scene as it relies on your system RAM to grab the frame, which is far less efficient than the direct hooking method used by game capture.
Game capture grabs the frame directly from the graphics card for OBS to encode before sending it back to the graphics card for final rendering of the frame.
Monitor capture has the graphics card write the frame to system RAM (Which is really slow to write/read from) before OBS grabs it to encode, then sends it back to the graphics card to render for final output.
If you want to use Monitor Capture, you should create a scene for it by itself without any other capture methods included in that scene.
Your webcam settings is hurting your output performance as well, if you lower your resolution to 720p it will help a bit in getting some load off your CPU.
You should try using CQP for local recordings, instead of CBR. CQP allows for variable bitrate, set to a pre-determined quality output.
Try a value of 15-23, High Quality preset, High profile.
CBR is designed to limit bitrate, really only desirable for streaming due to the restricted bitrate.
You are forcing compatibility mode, which is designed for X-Fire/SLI configurations. This is effectively the same as Monitor Capture as it uses your system RAM, which is quite slow in regards to performance.
If you do not have SLI configuration, you should un-tick the checkbox in the source settings (Little cogwheel, bottom right of source window)
If you don't already:
Limiting your frame rate in-game will help a lot in getting the best quality out of your hardware in regards to recording/streaming. I recommend using MSI AfterBurner or EVGA Precision to cap your fps to your monitor refresh rate, or 1-3 frames higher than your monitor refresh rate will generally resolve the issue of screen tearing. Try to avoid V-Sync as it can induce input lag.
I hope this helps improve the issue to a large degree, please post back with a new log file after you've adjusted settings, etc.
