Alright so when I record stuff, I usually plug my amp into my computer via the line out on the amp, a 1/4 to 1/8 converter, and a 1/8 to 1/8 cable going into the mic line in on the computer. Now all of a sudden it stopped working and I can't figure out what's wrong.

I've tried another cable and converter and I still get nothing. I plugged it into the back instead of the front and made sure the input was correctly selected but nothing is changing.

go though all the control panel settings for audio as well as your input source in whatever software you are using.

if you have a line in, use that instead...
if you are running a dynamic mic into your sound card run to the mic port, youll need that preamp.