I KNOW THIS SOUNDS BP AND SUPER BETABILL BUT THIS CONECTION WAS THE MOST STRONG THINK I EVER FELL AND SHE IS THE REASON I START WITH THE RED PILL

I will try to make it short. When I was 14-15 I start a friendship with this girl (she was in a relationship at the moment) so we were just friends but with a realy big connection (the kind of shit you see in a movie) eventualy we star dating but she friendzoned me. After 2 years of that (17yearold ) she try to get my attention again and we star the stupid circle again but this time again she fucked up and she start a new relationship with other dude and block me of every social media... Now (21yearold 2017) 3-4 years later she's still with this last dude but now she is searching me again (I think, she stars to follow me on instagram) and I dont know what to do (I didnt follow she back). I dont know if you understand but this connection was realy big shit (I never feel it again with anybody) and we were like boyfriend and girlfriend for a time but one part of me sees her in a relationship and knows that she will use me again but my weak side realy wants her back in my life. So what should I do?

PLEASE FORGIVE ME FOR HOW I EXPRESS MYSELF AND I THANK YOU VERY MUCH FOR YOUR ANSWERS