Every girl i meet steals my best friend?

I'm not a very forward person or maybe i'm just unlucky but it seems to me that everytime i meet a girl with my friend, my friend just gets stolen. Like just now, good friends for about a year.. meet some ***** and my friend is gone. I feel so sad about this because most of the time in my life i was alone to begin with, but why is it everytime i get a friend some broad has to steal him from me. Is there any way to overcome this? I haven't felt so much pain since i left my girlfriend because it wouldn't work out. I'm considering just letting him go at this point as a friend because he's no use to me as her puppet. Everytime i see her i have an enormous escalating anger building up inside it's just ridiculous how everytime i thought about this it just ******* happened. And to top it off we're in the same college cl, and since we're such good buds we decided to take the same cl next semester. What do i do? I will definitely leave them alone at this point because that's just what happened with most of these cases. My only concern is if you guys could help me deal with this, what actions should i take, what behavior should i set myself for? I've never felt this much sadness in my life it's so miserable..