Get a new amp. The Bandit 1x12 is okay for practise, but it will not cut it live. Try to get a half stack. A tube amp would be best, but you could try a modeling amp. Don't settle for less than a 2x12.
Tone is vitally important to a gig, make sure your sound is as good as possible before the show.
Going direct into the board isn't a very good idea, your tone will suffer, and you'll have trouble hearing yourself.
If you can't get a better amp, try to set your amp on something so it's closer to head level.