To start off with, you have a number of other issues present in your logfile upload. Will assist in further troubleshooting (If needed) as well once have got your bandwidth related frame drops under control.
Standard internet speed tests are not indicative of actual throughput for streaming performance/potential. Can you go to the below link and download r1ch's TwitchTest utility, it will assist you in finding the best Twitch ingest server for your location to stream via:
https://r1ch.net/projects/twitchtest
It is best to do a medium length test duration.
Once it has completed choose the server that as first priority, has the highest Quality and second priority, the lowest RTT (Round Trip Time)
TwitchTest utility will also provide the estimated potential (Will only display up to 10,000 kb/s) bitrate you can stream to for each particular server as well, which may or may not assist you in regards to your upload speed.
For the other issues present in your logfile:
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)
For your scene 'PUBG':
Using Monitor Capture in the same scene as Game/Window Capture can have a detrimental effect on performance as Monitor Capture is essentially 'always on':
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.
You have a number of files that have failed to load, you should check the directory structure you have set in OBS to make sure it correlates to where the files are located on your HDD/SSD.
Your Elgato Capture Card is set to a resolution of 640x480, is this intentional or by error?
You have a number of memory leaks present in your logfile, not sure how many of them are attributed to the failure to load file errors. Will have to wait and see on that one.
For better quality output:
You could use Lanczos downscale filter, found in Video Settings options of OBS.
Once your bandwidth issues are sorted, you could increase the bitrate towards ~5.5k (Twitch has a limit of 6k bitrate, which you have to allow for audio bitrate as well when setting bitrate) as that will look far better. The drawback is some of your viewers may have issues with potential buffering/hitching, just be mindful of feedback and adjust accordingly if it is warranted.
I hope this helps you out!
