Airplay won't stop trying to connect and internal speakers don't work

Yesterday I was listening to music (not iTunes) through my headphones when all of a sudden the sound stopped working. At the same time, a window popped up asking me to enter the Airplay password of a device I did not recognize (I was in a public location). Any time I tried to adjust the sound, the same Airplay window would pop up. I thought when I went home the problem would be fixed because I would no longer be in range of the Airplay device, but I still do not have any sound through headphones or the internal speakers. I don't even get the startup sound when the computer turns on. I have tried plugging and unplugging my headphones several times to reset that sensor, but nothing changed. There is no red light by the headphone input, and when I go into settings there is no external output option (see picture). Also, whenever I press any of the volume buttons on my keyboard, I get the the second image. I have restarted my computer, and searched everywhere for solutions, I have seen a few other people with the same problem but so far no solutions. I have a 2011 MacBook Pro and am running OS X 10.9.5