To be honest, it's been a while since this has happened, yes? Forget the phone calls, e-mails & shit, go see him when he's not expecting you, when you know he's in & have this out. Because if you don't, the longer you leave it the harder it's gonna be to try & repair any damage. This is eating you inside & that ain't healthy. One way or another you have to get this out of your system & talk to him. I would strongly advise against using the love word though, that won't help your cause. All you can do now is get your best friend back, work out the rest later.
Good Luck.