I'm guessing you went to high, and it broke, some chromatic tuners recognize just the note, not the octave. Try using the tuner on the site, or something that has a tone so you can hear the notes.

I don't know much about that amp, but as long as you've got distortion you can learn to play metal.

Let me know if this helps, and just one other thing. The 6th (big E) string in the 1st fret is an F note, same as the dial tone on a phone.

JD