So my best friend is dating the guy I have had a crush on for so long and got so close to him: and now I don't even know both of them and they both pushing me away:mad: , should I let them go or try and get them back? But either way I am hurt :(

It depends on what you mean by pushed away. Are they excluding you or are you being impossible because you are not happy with the situation? Do they just want more time alone or is your friend afraid you are trying to take him away from her?
I wouldn't make problems or ultimatums or anything just go along with the flow and see where it goes. IF they were to ever break up they (one or both) may want your friendship back if you don't push the issue.

I know you are hurt hun, but if your friend wasn't big enough to tell you that she liked him too, then I say, better off without the chick! Boys come and go (literally and figuratively) but friendships are forever... when their relationship ends, she will be hurt and need you to talk to... but oh yeah oops she screwed you over and now you've moved on - hang out with your other friends, don't talk junk about her (as much as you want to) and time will heal your hurt. Betrayal will come back to her in the end.

Yep just leave her go her way and only be there as much or as little as YOU want and it will all work out in the end however it is meant to