I met this girl that was a friend of my friend and we cuddled together the next day. Now I'm not sure if it was because I'm a completely nice guy or if it's like love at first sight where she likes me instantly. Also when It was time to say goodbye, she gave me a hug that lasted longer than a hug you'd give someone you literally just met. So what I want to know is if she is hitting on me or just being nice.

I know I'm not that old but your building off the cuddle just wait a little while and see were it goes if your older or something you should call her and ask to hang out sometime.

She completely cut me out of her life by ignoring me a week later. I hate my life.

Ah - so you are letting someone else determine how you feel about your life? That doesn't sound too healthy, does it? If you are going to allow people to control how you feel, you are in for a very long and sad life.

Learn how to take control of your emotions and feelings. Nobody determines that I am going to have a bad day so generally speaking I never have a bad day. If someone determines that they don't want to be your girlfriend or they don't want to be your friend, there is basically nothing you can do about that. So accept it and then go out and have some fun.