ACCK! WHAT IS WRONG WITH ME!!!!!

my last serious relationship ended VERY badly ago 2 years ago. I've been praying for some guy to come along that'll be kind, funny, caring and accepting of all my little faults unlike my ex. Lately I'm seeing that my prayers may have been answered...the only problem is the guy who's amazingly 'sweeping me off my feet' kinda happens to be the older brother of one of my best friends. Is something wrong with me?? I mean he's always been dear to me but is it stupid of me to be falling for him like this? should I NOT respond to the affection he shows cause he IS my best friend's brother? I mean what if he turns out to be the one guy who's right for me but it ruins my friendship? or if I ignore the connection WE have could I be missing out on the greatest thing I'll ever have?
should I risk getting crushed and give my heart to him and see if he'll take it?
or should I try to forget these thoughts and try to find a 'safer' guy that I don't have to give so much up for?
Im so confused...anyone have any thoughts to help???

-Samantha