molested as a child

So I was watching a YouTube video about a brother who molested his sister on dr Phil and I guess it kinda brought something up that I had buried. When I was maybe four or five, my house was right in front of a neighborhood park I liked to play at. One time while I was out there by myself, a boy named Talon came up to me and made me lay down on the park bench. He proceeded to pull my skirt down and touch me over my underwear. I quickly tried to shove him off me and pull my skirt up and he started screaming at me. I don't remember whether or not I told my mom, and I hadn't thought about it again until now. Back then I don't think I knew that it was wrong for him to touch me but now I feel like it won't stop replaying in my head. It shouldn't be a big deal cause it happened so long ago and I haven't even remembered till now. I want to tell my fiancé about it but I don't know if I should or if it's even relevant. Help?!