I don't want to end up in the friend zone..

I met a girl in my philosophy class a couple of months ago. She's incredible. No girl has been able to make me this happy since my last girlfriend. I'll spare you the details of why I like her so much. At first we were just friends, but last week we started hanging out a lot. She would come over and we would just cuddle and watch movies and laugh. It was amazing...

She texted me last night saying "Hey Justin, I really like hanging out with you and everything but I don't think I can do the late nights anymore. This is all too much too fast. I hope you understand. Let's Just keep this at a friend level. I'm sorry..." Just to clarify, all we've done is cuddle. I haven't even kissed her.

Her Tumblr account has hundreds and hundreds of posts about never trusting anyone again - heartbreak stuff. I get it, she's not ready for a relationship. She may not be for a long, long time. But I want to be the guy when she's ready to move on. And this is where I get confused...

This exact same thing happened to me in high school... The girl I was crazy about still liked her ex-boyfriend. So I became her best friend in hopes that I would be her choice when she was over him. Well, that didn't work. We dated for a couple of weeks and then we broke up. A few months later we became best friends again and I forgot all about a relationship with her. We always go to each other for dating advice. Just to be clear, I don't like her like I used to. She's like my sister now.

So naturally I asked her for advice on this girl I like. I asked her what to do and she told me this: "You need to get outta there before you get stuck in the friend zone. The only person who can help her is herself:/ I feel for her. Just think, why did we break up? Because I wasn't over someone and I wouldn't allow myself to see you any other way. I couldn't. You were there at my worst time so I loved you for being there for me... but that is all it would be. Doesn't matter how amazing or attractive you are.. timing is everything in this situation. Make sense? Just don't let her confide in you too much. Then you become a walking bank of bad memories. Stay fresh for when she is all better. She will find someone else to tell all the junk to. Trust me. You don't want to be that guy. She might date that guy but it won't last very long. And after that is over, that is when you come in to get the best of her."

Everything she says makes sense, and it's almost funny I was that guy who she confided in and now she's using me as an example for this new girl. And now that I'm pretty much in the exact same situation, I'm starting to freak out... I already told this girl I like that I'll always be her friend, no matter what. What if she starts trying to confide in me? Have I already ruined things by getting affectionate with her? Do I just stay the bare-minimum friend to avoid becoming a 'walking bank of bad memories'? And equally important, is that good advice that my ex gave me? Any help/advice at all would be amazing.. I'm sorry for the long read, this is my first time ever coming somewhere for help. I don't want to lose this girl. I don't to look back a year from now and be in the exact same position that I am in with my ex. I don't want to be just a friend.