I need help.

I'm sorry if I sound immature, but I don't know how to deal with rejection. I just don't have that much to look foward to if she rejects me.i know this sounds very petty. Honestly I don't think I will ever find a girl as good as her. I just need some help because she is the reason I've been improving my life. I have her phone number and we've been talking and everything. But im afraid there is a chance she will reject me. And I know it sounds fucked up to leave my friends and family all because of a girl, but if she rejects I don't know what else I would do. I feel childish for posting this, I feel like much more people on this subreddit and off of it has it a lot worse than me, but I don't know what else to do if I get rejected.