"Like so many other kids with special needs, I have been bullied," says Potter, 20, who has Down syndrome. "Kids in elementary school made me eat sand, and those same boys would walk behind me, teasing me. Finally I had enough, and I told them to 'grow up.' "
Potter is teaming up with AbilityPath.org to help end the taunting of kids with special needs.
"I joined because they are a great organization and the issue of bullying must stop," Potter tells PEOPLE. "AbilityPath.org has great resources for families and is committed to ending bullying. I know I can help bring attention to them."
Potter and her mom, Robin Sinkhorn, have joined the nationwide Disable Bullying campaign on the site in partnership with the Special Olympics and Best Buddies. The organizations released a report on Feb. 15 called "Walk a Mile in Their Shoes" that showed how children with special needs are more likely to be the target of bullying in schools than the general student population.
"A lot of times, parents don't even know their children are being bullied," says Sinkhorn. "Children don't even know because they're so trusting and so longing for those friendships that people take advantage of them. That's one of the reason this Disable Bullying campaign started."
Potter, who is a fan favorite on Glee, says she still sometimes experiences bullying. "Recently, I've had girls say behind my back, 'retard,' and that is so hurtful. It's also why I support the Spread the Word to End the Word campaign."
But the actress and her mom are both grateful for Becky Jackson's prominence on the hit show – as well Potter's fans. Potter, who now carries headshots and a pen so she can sign autographs for admirers, hopes the spotlight does not only further her career, but also gives her a platform to help others.
"I want to encourage kids to speak up, to tell their stories," Potter says. "That is the only way people will know what we have to go through. Believe in yourself. Someone once told me being different isn't bad – different is just different!"