I fuck things Up

Hello world 
I want to tell something its always inside me 
It makes me nervous when any girl stares at me 
Its obvious she is attracted by me and me too by her then why i fuck things up in last moment  
when she try to reach me i always change my path 
i feel so nervous and tensed at that time my heartbeat starts increasing 
and to calm myself down i run away from that place and from that girl 

so many times this happen with me 
when something is beginning to happen i just fuck things and after that i think about it 


i don't know how to deal with this situation 
One more thought always come in my mind if she says NOO then ??? 
My friends have 3 , 4 girlfriends each they are very lucky they just go and do it . 


It needs a lot of courage and i don't have that much courage inside me  
hope i will change myself soon 
Girls attract me a lot whoever i go to mall or some other place but i  always miss  my chance 
because of my mistakes 
I realize this habit of mine i will try to change myself