over what "48fps" is
Unless OBS is doing something really crazy, 48 there really does mean 48 since they are omitting the NTSC unlike the 24 fps option. I would also imagine twitch wouldn't have any issue with a NTSC framerate either way, but I'm not a twitch engineer. You could always try setting the fps manually with the integer values option, if you really want to be sure, but again, I highly doubt that is the issue you have.
just realized my audio doesn't even stutter during the 2 examples
When you drop frames on twitch, you are just dropping visual frames not the audio stream, so that issue is just another confirmation that you are experiencing frame drops. As a side effect, this is how a viewer can tell that the streamer is having stream issues rather than their own issues which would cause the entire stream to freeze.
While I can't say for certain, I'm pretty sure your issue is a "it is how the internet works" issue and not a "you" issue, especially since your local recordings work fine. Just because your bandwidth isn't choked up doesn't mean any of the hops along the way to twitch aren't. Outside of paying for a business internet connection, which should solve issues from you to twitch, there really isn't much you can do to fix that issue. However, you can definitely try changing your twitch ingest server which can both change the hops your connection uses and give you a less congested server that can handle your stream without dropping.