Sorry to hear this, you yourself gave a good example what to do. Telling your parents is the best thing to do here. Ask them if they had this when they were in school and if they think it's a good idea to talk to a professional. If this is a bridge to far, talk to a professional at school. Not sure if they have it at your school, but in my opinion they should. Those people have a obligation to help you and if you want they cannot tell your parents.
Do you play videogames with any class mates? You could ask them online to meet them after school. Start with something small, for example it could be that someone has to go into the same direction as you when you are going home and you can ask them to walk/ride/take bus together.
Other then this it's hard to give more advise, things will get better when you're older. You have to believe that you can do it, that is the first step. After which things like this will get easier.
Good luck!