I feel like we put too much emphasis on confessing and forget who we are confessing to. I feel like if you are mature and 'confess' in the right way, then you don't have to worry about the other person freaking out. Remember OP, he is your friend, and if he is a true friend he will be there to help you out, despite your problems.

OP just one day sit him down and be completely honest with him and use language that won't scare him like "I LUVS YOU!" No, just sit him down and say like, 'We have been good friends for awhile and I feel like we have a better connection that other people...blah blah blah...I have started to develop feelings for you and I want to tell you because I trust you and know that you will know how to handle the situation...blah blah blah etc' I dunno, something like that, just be honest and try to keep an open conversation to sort out this situation. Again he may feel the same or he won't but that is a leap of faith that you will have to take. But talking from experience it is better than sitting around and wondering what could have been.