What did you fill the container with?

Depending on your mix, size of plant relative to its container size, type of container and weather, you could need to water so frequently but that doesn't usually happen for me untill later on when temps are upper 90s, no rain for extended periods and fairly lrg. plants.

Over watering and over fertilizing ... Over loving the plants are common new grower mistakes. Feel down in the pot with your finger several inches. If its moist, don't water and observe the plant for a few days. It takes a little longer for them to heal up from over watering than being too dry.

if the tomatoes are turning yellow than its could be some infection. and yes l think you are over watering

Here is a link that might be useful: Tomato growing problems

You're probably experiencing an overwatering symptom. Also, make sure the plant isn't rootbound. Tomatoes have quite a large root system and if rootbound the leaves will droop and sadly beg you for more room. Put them in a BIG container and watch them smile and turn bright green. It takes about two days to see the results. Oh, and rough up the roots a bit so there's plenty of soil contact.