How do I overcome my memories of bullying?

When I was in secondary school I got bullied a lot, in fact they tormented me every day and I was on the brink of commiting suicide. Well, I'm out of school and away from the bullies now but lately I'm worried whenever I go out I might run into them and I keep remembering how they used to bully me, I don't know why but it's really been bothering me. In fact, I'm worried they might be right out my house. How do overcome my fears and memories?