Is freezing a fish a humane way to put it down when you can't get Clove Oil?

My poor goldfish is suffering. Lately she's been slowing down, she's getting old. Two years on her belt. I'm 13, and my fish has lived a good long life, and she seems to be suffering. I'm not sure if I should freeze her, I can't go to the store and get Clove Oil...I'm not going to flush her down the loo, but I'm going to bury her. Ellie is suffering, she's old, and slowly down. So, how should I kill her. I'm 13, and I can't get Clove Oil. If it helps any, my dad owns a liquor store. Something about distilled vodka...