Some time ago I've been rejected by a girl; she friended me. (Do they realize how fucking cruel the word "friend" is? How it hurts and destroys person's whole life?) I realize I'm a fool for not realizing sooner that she doesn't want me (or maybe not wanting to let go off hope by confessing sooner) but what's done is done, and now I'm seriously fucked up.
One of the best ways to get over somebody is to move on. Try and find somebody else to go out with, even if you don't throw yourself into it fully and it doesn't turn into something special then it should help you get over the first girl so you can see without feeling hurt.
Even if you share friends, you can reduce exposure. You could even explain herr the situation, so that she doesn't misinterpret it. Once you regain your balance, you can again be closer.
The Cut Off has been the only thing that did well for me, unfortunately.
This is not intirely a bad idea. I had to the same to get over someone. It got to a point where I'm like "I have to cut her off". I never told her and just ignored, and while it was working something she did (she was looking for me very worriedly as to why I was ignoring her) made me like her again, though briefly, since when I saw her she acted like she wasn't doing worried about me. In the end we went our seperate ways and after some good time effectively got over her, so I was able to somewhat becomes friends. Now though, we seem to be having going on between us, though I may be looking to much into it AS USUAL, but we're in a good place. Not sure if the same will happen to you OP, but I might reccomend that you tell her to avoid that drama I went through because that left me utterly confused and delayed the getting-over-her process.
There are ways you can fix this, but you have to be a good flirt...
Ask her out again. This time, tell her that you want to take her out for a good time. Smile, but don't be creepy. BE HER FRIEND. She must feel safe. She must enjoy being around you, or she wouldn't be your friend. If she tells you no, be persistent. Not stalker-ish, but persistent. Ask why she doesn't want to, say something like, "Oh, why not, are you busy?" If she says yes, make a mock-sad face and say, "Oh, all right, I won't bother you" and overly exaggerate slumping your shoulders. But afterwards still treat her like a friend. She would like that. Continuity. Let her know that you are still going to be her friend even after she turns you down, or even after you start dating.