What do you mean by reverting everything though? How would I do that?
In this case, it means that you have to get rid of the version that you have currently installed. You can do it easily by typing in
sudo rm -r /usr/local/go because you have installed it manually. If you get 'Unknown directory error' or something similar then you must have done something wrong in the first place. Don't forget about the second suggestion if the first one doesn't work for you.
Will definitely try the second suggestion if the first one fails! What exactly does that command do? (sudo apt-get install golang)