I love my best friend, but I value our friendship a lot too. Should I tell him?

We haven't known each other for a long time but he's a very valuable friend to me, especially since he helped me get over all the **** my dad did to me (my dad was abusive to me and my little sister). As cheesy as it is, he's one of my few friends and his words helped me through this tough time the most. I've always had feelings for him, but I didn't realize until he almost kissed me when we went out for drinks a month or so ago. I don't think he like guys at all though, since he was engaged to a girl for almost a year (before we were friends) and he's dated a lot of girls before that. It's really hard to hide my nervousness and it's making it hard for me to hang out with him, so I want to tell him even though he doesn't feel he same. I know he won't tell anyone or be super disturbed by it, but I'm scared that it'll ruin our friendship. What should I do??