Unable to authorize computer and download purchased music

Hi friends! I recently bought a couple of albums on my phone. Afterwards, I got a new set of headphones and was gifted 6 months of free Apple Music.

After setting it up, I tried to download my new albums into my computer but I got a message saying that my computer was not authorized.

I followed the steps listed here but then I got this message saying I couldn't authorize more than 5 computers.

So I went into the account settings and it turns out I only have 1 authorized computer, not 5, and I don't get the option to deauthorize all of them.

And I can't for the life of me figure out what to do. HELP PLEASE!