Vauxhall Corsa sxi 1.2 53 plate?

When the engine starts the engine settles and there is a knocking noise coming from the front of the car. When driven the knocking noise will get quicker as I accelerate. I was told I would need to replace my timing (cam belt) before it completely breaks..I had recently sparks replaced due to lost of power when accelerating. All these problems have popped up in a week. Never had a problem before. Thanks