Ok so I figured it out myself. As someone commented before, yes, I already have pavucontrol, but that wasn't working for me either. What I did was I made a virtual sink and a loopback of said sink. To do this, I used pactl load-module module-null-sink sink_name=vsink to create the sink, and pactl load-module module-loopback sink=vsink to create the loopback. Then I put the application that I wanted to record audio from onto vsink, and put the sink's loopback onto my desktop audio. This works when I run the commands through terminal but strangely doesn't work when I run them as a bash script. Instead of creating a sink and loopback it creates a loopback of my microphone. However I'm fine with the way it is now that it works.