Do you know your soil's pH value? Looks like Macro nutrient deficiencies. If you've never flushed your soil before, now would be a good time to do it. That will reset your soil with the pH you want, and to flush out built up nutrient salts that could be causing your plant to burn and be deficient due to lock out.
Depending on the size of your pot, for example, if you had a 1 gallon pot, you would flush pH adjusted tap water through your root zone with 2 gallons. Then allow the soil to dry out so the pot feels light again, then feed with a balanced, pH adjusted nutrient mix.