Tomato Disease?

I am sad to see my tomatoes seem to have a disease. If any readers out there are familiar with this disease, let me know! Also, if you have a natural solution to this problem, post a comment! My fruit trees seem to be having the same problem. I am new to gardening, so it's a learning process for sure.

Update: My father-in-law told me my tomatoes have calcium deficiency. So I am starting over with new tomatoes and spraying them with blossom end rot spray that helps to correct calcium deficiency.