Recently there was another question about tomato symptoms very similar to yours. Here was one answer
https://garden.org/thread/view...
You might benefit from reading the whole thread, in which several possibilities are put forth.
Re fertilizer: if your tomatoes are confined to containers and not in ground soil, they need to be supplemented with a full range of micro- and macronutrients, not just NPK, required for plant health. Find a fertilizer that provides magnesium, calcium, sulfur, boron, zinc, manganese and molybdenum as well. Resist the hype of "bloom booster" products with super-high phosphorus; those have been discredited as unnecessary and counterproductive. However, there is such wildly conflicting information specific to fertilizing tomatoes
in containers that I can't begin to recommend any particular product except to suggest one that is reasonably balanced and contains a full spectrum of nutrients.
How you calculate the strength when you mix fertilizers depends on how you mix them. Do you pour them into another container and then use the recommended 1 tbsp per gallon of that mixture? Or do you add 1 tbsp of EACH fertilizer to 1 gallon, on other words, 2 tablespoons total? It matters.