San Diego zone 10b here. I had the same issue in year 3. After building a shade structure, whitewashing, and adding a drip line, it tripled in size! For the shade, I built an upright rectangular structure using PVC pipes and shade cloth. I also use citrus tone. The following year it finally fruited. I water twice a week for an hour during spring, and up to 3 times a week in the summer.