Also, now I can hear from the speakers as well, but the volume is very low, just like the headphones. I have to like press my ear against the speakers.
All of my other computers are laptops, so I don't think I can connect the speakers to them. Also, since this problem is also happening with the speakers integrated in my monitor, and my headphones, I think it's the computer. The headphones work perfectly fine with my iPhone.
UPDATE: I plugged the headphones in and tried to do a sound test and watch videos, but the volume is really really low. I had to have perfect silence to hear it. The volume is turned up all the way on my computer in the sound icon, so I don't know why the volume is really low. This probably...