How Should I Beat the Final Boss in Silent Hill Origins with these items?? HELP, I'm scared!?

Okay, i'm not really scared, but I'm frustrated. I keep dying trying to beat the fire-raining final boss. I enter the scene almost dead, and all I have is an Ampoule, 9 Target shots, 18 ault rifle, and 9 redeemer. Then you know, energy drinks and Melee, or whatever it's called... I need some ideas on maneuvers?