Should I tell the girl I love that I love her?

[Brandon]

Yes, I know love is a strong word, but I LOVE this girl. Her name is Brooke, and she has the most amazing eyes, and... well, I'm getting carried away.

Anyways,
Back about a year and a half or two years ago, I asked her out and she said no because she didn't want to be in a relationship. I asked her out over Facebook (I know, I know) because she was out of the area, and my best friend Phil was right next to me when I did it.

I told Phil that I loved Brooke, and he really acknowledged that (so I thought).

As of about a month ago, Phil and Brooke are dating and kissing and shit in front of me. Phil fucking knew that I was in love with this girl, and I still fucking am.

I know that she has a boyfriend, but should I tell her how I feel? Will this ruin my chances with her in the future? Will this make me seem like an asshole?

Thanks guys.
Edit:

I forgot to mention that we're best friends. This is a friendzone situation