UPDATE:
I took the bike to a bike shop, where they used a powertool to remove my bottom bracket in a matter of seconds! And didn't even even charge me for it

Now I have a new issue: I asked the dude for the size of the bottom bracket so I could get a new one and he told me 122. I'm finding it hard to believe that's correct and unfortunately I didn't bring the old one home with me. See, the part of the frame where the bottom bracket goes into is 70mm wide, so 122 seems way too wide, even considering the part that sticks out. Is there a way to figure out the size of the bottom bracket based on those 70mm?