I am in a similar position. I am in love with a good friend too(Mad Scientist). Mad Scientist and my partner (Gamerboy) have been friends since elementary school. All three of us have been hanging out regularly for two years now, and in that time, Mad Scientist and I have become good friends. It wasn't until early this year that Gamerboy pointed out that it seemed like a lot more than friendship, (we're both poly).
I am still trying, unsuccessfully, to deal with those feelings. Mad Scientist is aware that we're poly but I have yet to be forthcoming about my feelings for him. After an frustrating miscommunication on Friday, we talked and he said he didn't know he was allowed to see me as anything other than "one of the boys."
I didn't tell him I had feelings for him but did say that more was bothering me than I was letting on. The conversation probably left us both confused and with food for thought. Long story short, I can relate and if you want to talk about it, I'm here.