Reverting to a three year old state of mind

I'm starting to see that maybe I revert back to a younger state of mind.  I see my "Best Friend" walking with someone else, someone else holding his hand laughing with him and its getting to feel like he has no time for me anymore.  And even so it seems silly sometimes I want to yell when I see them and shout "THAT IS MY BEST FRIEND!" because it hurts me deep inside and I don't know how to handle it.  I want to be able to hug him and cuddle him and hold his hand.  I want to hear him say he loves me still and I want to hang out with him and laugh and have fun.  Is that too much to ask really? I just want my best friend back and I want to tell him that but I know that he wouldn't feel the same way I can tell by the way he walks with and talks to my replacement.  That may be what hurts the most. Replaced.