I would start over. It's been a really long time since I've done seeds indoors but very little or no direct light for a while, rotate the box 1/ 4 turn every day. You could try to pinch off half of them and see how they grow? Try leaving the dome off for a while too. Did you get just 1 seed in each pod? I used to always do 2-3 seeds per pod- pull out the spindly ones and leave the shortest/healthiest looking one. Once they get established they need some minor airflow to strengthen the shoots. Good luck!

Start over. Plant two to three seeds per cell and remove from the heat mat as soon as they germinate. I also remove the "greenhouse dome" at this time. After the true leaves appear, thin to the strongest seedling per cell. Place in a southern window and open the window on warm days for a breeze or place a fan in front of them. The air movement will make the seedlings stronger and stockier. A mild seedling fertilizer such as PHC will do wonders. Put them outside on mild days in filtered sun. Gradually increase to full sun over a week or so. Then, if all chances of frost are past they are ready to put in the ground.