I'm suspecting your OBS settings are wonky from Internet advice that is either flat out wrong/misleading, or doesn't explain the caveats, or maybe just your misunderstanding. So others can see/advise on your settings
Though, this is free open source software, so the expectation is that you do your own research, but as you have obviously done some research
Per pinned post in this forum
OBS Studio creates a log file each time you run it which contains very useful diagnostic information. Without a log file, it's much harder for any support volunteers to figure out problems and your post may be ignored. To upload a log file, go to the Help menu > Log Files > Upload Last Log...
obsproject.com
And always good advice
Here's the quick-start guide:
OBS Studio - Free and open source software for live streaming and screen recording - obsproject/obs-studio
obsproject.com
I'd also recommend watching the Nerd or Die tutorial video series:
Welcome to our OBS Studio tutorial series! In this series we're going to cover everything that you'll need to know to make your stream look great.Next Video...
www.youtube.com
Your CPU should be more than adequate for non-demanding gaming and encoding
As basic troubleshooting step... don't stream, only record (removes network from equation). How is recording? if bitrate, etc all fine, then not OBS but most likely the network. For now, stick to OBS auto-config basic settings, and make sure you aren't in Studio Mode (dual output render)
recording quick notes
https://obsproject.com/forum/threads/best-settings.140188/#post-514693
Sorry, I can't be specific on the AMD GPU, as I have and my experience/research is all on nVidia's NVENC