Q: I had the worst year ever for tomatoes. The plants didn’t produce as many tomatoes and the tomatoes themselves were smaller than normal.
A: I think it was just the vagaries of your local environment. Several things can cause small tomatoes. Incomplete pollination, cloudy days, too much heat at the wrong time, not enough fertilizer, etc. could all be causes of poor fruiting. Sometimes you just have to roll with the punches and look forward to next year.
See Small tomatoes