How to deal with this? Question about liking a friend's guy?

So I am like INFATUATED with my friend's boyfriend, like literally, I can't sleep, I can't eat, all I do is think about him. The thing is, he is PERFECT. Best runner in the school, does two levels higher in math and gets great grades in everything. So, he asked my friend out last year, at which point I didn't like him because I didn't know him and I was super happy for her, right? So, it hits me like a week ago that I love him, and I'm not sure what to do. I guess his gf isn't really my friend anymore...we don't have any cles together, so we never talk, so I guess we're not really not friends, but I just think its so cute, for them to be together. I mean, his face literally lights up when he hears her name or sees her face. Its too cute, and I cant help wishing that it was ME. But, I am happy for them because they totally belong with each other. Sometimes I get the thoughts like "What does he see in her?" she's not pretty, but she is amazing in her ways. She is pretty short too...like shorter than everyone, about four like five...everyones around five and up. I still like her though. I don't have any bad thoughts towards her...should I tell her I like her boy? Do you think she'd be cool with it, or would she freak out and tell him? She's not a clinger really, and she's pretty cool with everything. I don't know...distressed!!!!