I had a terrible nightmare and Im scared to go to my mom, what do I do?

Just remember that it was only a bad dream. I've had problems with nightmares off and on. talking about it does usually helps. what better person to talk about a bad dream with than your mom or dad? I've talked with my mother a couple times about some of my bad dreams and it helped. Another thing that helps is prayer.
Just in case, if you watch a lot of violent or scary movies or play a lot of scary or violent games, that also can effect your dreams. If so then try playing and watching less violent or scary movies and games.