maybe looks like a nutrient deficiency, which could be caused over or under watering or lack of correct fertilizer or a combination thereof.

What size is the container, and what mix did you use?

How often do you water?

What fertilizer do you use, how much and how often?

How many hours of sunlight per day?

to be honest, don' like your chances of saving it....maybe keep it alive to harvest the remaining 2 fruit.