I'm from South Africa. I don't know what the politics in the US is like and I don't know exactly whats happening. Most poignantly, I have no senator or representative to contact.
Can I still get involved? If so, how?
Yes, you can. From this answer in the question you linked:
Some might say that "foreigners" (non-U.S. persons) might not have a say in this, but as I said above this is one of the few times I encourage them to.
So as a foreigner, the specific form Shog9 linked to won't let you fill it out and send a letter to the FCC as you need a United States address, but the FCC has a contact page, so you can still tell them to suck-it (figuratively speaking). You can also view official comments on this proceeding and add your own, simply click "+ New Filing" or "+ Express". (You can even upload documents if you click "+ New Filing".) And if for some reason that link quits working, search for proceeding "17-108", that's the "Restoring Internet Freedom" proposal to eliminate net-neutrality.