Start to sink is a phrase that describes the beginning of a process in which something gradually descends or falls. It can be used to describe a variety of situations, such as a ship sinking in the ocean, a person's career going downhill, or a business losing money. The term can also be used metaphorically to describe a situation in which someone is feeling overwhelmed or discouraged. In this context, it can be used to describe a person's emotional state or a difficult situation they are facing.