Dude...first of all get a new mic

ouch.
I don't think you have a bad voice @ all. But dude, don't take voice lessons. Practice w/ someone else playing guitar and please go to Guitar Center and buy a decent mic (you can get an audio technica for $75).
Also, try and get guts enough to sing in front of other people w/ an accoustic guitar or piano. This will help build up your confidence.
Good luck young skywalker.