tomatoes like hot weather, all day full hot sun, deep beds, consistent moisture-
They've outgrown their pots, for sure, so they are not getting consistent moisture- they're going very wet/very dry/very wet/very dry- they hate that.
they don't have enough light- if I spent a day in tomato happy sun i'd have to wear 50 sun block and sit under and umbrella to not end up fried to a crisp- but just like people, they have to be moved out gradually so they don't burn....
the thing is- if you ground is not warm yet or you get nights below 65 degrees and you plant them outside they're going to get stunted even worse-
if your ground is warm (which happens when your nights are warm) they can go outside- if not- bigger pots, brighter light is your only option.
so that I can get fruit early, I start my tomatoes early inside.. right now my tomatoes are in 10" pots 3" under two 96W compact florescents with high quality parabolic aluminum reflectors- that's how much light and root space for consistent moisture we're talking about. your overage 4' florescent bulb is 40 watts- I'm running 5x that in 1/2 the space...
If you want to get a jump on tomato season that's the only way to roll.