If your ankle needed surgery. but you just decided to wait would it eventually heal on it's own? if so about how long? or would it just make it worse?

Depends : Best to ask your surgeon those very questions. It depends on the injury, your health and activity level, and your ultimate treatment goals.

Healing: All fractures will heal on it's own in some way; the problem is that if bones are not correctly approximated and or not aligned the fracture could heal in the wrong position (mal union) or heal by forming another joint (pseudo arthrosis) or maybe not healing at all (non union). The ankle in addition will give you gait disturbances and possible chronic pain. The answer is do the surgery.