This is going to be kind of long but here it goes.

So there is a girl I like and I guessed her email and got it right. I confessed to her and she was fine with it. I was messaging her then she said I was annoying her so I stopped. A few weeks later I said hi and she didn't answer. I said hi the next day. Nothing. I kept trying but she wouldn't answer me. She blocked me on everything. I emailed her. Nothing. I kept emailing her and finally one today she answered me. She said In capitals that I was annoying her and she didn't want me to talk to her anymore. I just can't stop thinking about it. Can someone please tell me what to do?

Your age would be useful to give valid advice for your situation.
Ps don't be a creep, she clearly doesn't want to play your games..

Take the hints and leave her alone. You have had MANY warnings. How many do you need?

She told you to stop bothering her and you kept on doing it...she blocked you and you still don't get it. How about toning down your obsession? Bothering her like this isn't going to make her be all over you and want you as a boyfriend.

We can only guess what you might have said to her when you "confessed" and you probably creeped her out the more she thought about it.

Time to get the message...she doesn't like you that way, you're bothering her, she told you to stop...move on and find someone else to latch onto.

Stop bothering her... she made it perfectly clear to you. Do you want to be known as that weird kid nobody wants anything to do with? That can happen really easy. And you will have to live with being that kid for a lot of years.

And here is a bit of advice... the more you annoy someone the LESS they like you... particularly girls. DO this when you get a little older....you could find yourself being arrested as a stalker.

And girls talk to each other about boys. Don't get a rep as a creep.