No sound output

My computer will not produce any sound!

I bought a tiny audio plug-in speaker to plug in to my computer to play sound. This has worked and I have been able to unplug it and still hear sound out of the built in speakers in my computer. For some reason, I just unplugged the speaker and now there is no sound coming out of my computer. I tried to turn up the volume but it shows a faded sound symbol and a circle with a / through it.

I went to the sound settings and clicked output, but all that shows up is "digital out".

I am so sad! I wish this could be fixed soon. Someone please help me! Thank you in advance!