The best you can do for them now is to place them in bigger pots and grow them indoors until you can place them outside.

March 15 is about when they should be seeded, so you're way too ahead.

If you have a small osculating fan, it would help strengthen the plants; just don't aim the fan directly at the plants, at least not at first.

I'm surprised your seedlings are leggy already, must not be getting enough light. I find that indoor tomato seedlings under grow lights do okay for about 6 weeks, then get leggy quickly, so I suggest starting new seedlings about 6 weeks before you anticipate getting them outside.

Tomatoes very readily develop roots from stem portions that are underground, so when you transplant your growing seedlings, sink the pot right to the bottom of the new (larger) pot -- that will help keep legginess in check somewhat.

Thanks for the advice. I am using a fan and will pot up shortly.

I have grown cherry tomatoes quite successfully indoors, so don't feel that they're done for.