I made my gf cry badly. I didnt mean it...what do I do?

Okay. I told one of my friends at a party that sometimes i dont like to talk to her because she is hard to understand sometimes. Well she heard me since she was at the party and. She told me and she started to cry and she walked away and hasnt talked to me for a week. I was so jerky and I totally regret it since she has a speech problem. How do I appoligize for that?