I need advice. </3

Alright, so I need advice..
I really like this guy. He's like amazing! But, hes a grade above me. I mean its only one year right? Well, yeah. Here's the story about him.:
I've liked him for a very long time. He is my old (long story) best friend's brother. He texted me, knowing I liked him and acted all flirty. And then asked if I liked him. And you know I tried to be like mysterious and say "Maybe, you never know(;" And hes like well, I like you too. And Then I told well, I really do like you. So for a couple days we just texted, and acted flirty towards eachother. Like he was my DTC (down to cuddle) buddy. We got super close. Then I went to there house to spend the night with his sister. She knew I liked him too, because I'm not going to lie to her or anything. So, we walk down to the park, and he's there playing basketball with all the guys. I was with my friend Mariah (Austin's sister), and Tristen (Mariah's bf [now ex] and my cousin). When Austin was done with basketball, he came up to where me , Mariah, and Tristen were. Mariah said she was giving us "alone time" and left. He was listening to music and then all of the sudden he kissed me, outta nowhere. I started giggling and I could feel my face get as red as a tomato. Then we were just hanging out. At the park there is like a little creek with a bridge, and we went over the bridge to a tree. Thats where Mariah and Tristen were sitting (and kissing. *shivers*) Me and Austin went over tot he picnic table and sat on it. He held my hand and took a picture of us and set it as his wallpaper. I felt like I was seriously in love, then he kissed me again. But this time, a like movie kiss! With no tounge but you know (I'ma skip through this part, bet you dont wanna hear about my kissing) and then he kissed me again the same way. It was around five o' clock, so we walked back to their house. Then we got ready to go to the roller rink. Thats when it went down hill. There were a couple guys in my grade there. 2 of them were in my class, and the other I have known forever but I wasnt really close to. They told Austin a whole bunch of lies about me.. and he stopped talking to me.. I told Mariah and she's like OH NU-UH and went to see what his deal was. And then he told her about the rumors and told me.. I would probably have no chance with him (*Note we aren't dating yet). I cried and cried in the bathroom. Then finally, the place was closing so we went outside. Their mom was late and it was freezing out side. I was sitting there like shivering. Austin was like "Are you cold?" and I say yes of course. Then he tells me to go inside so I do so, and he follows me. He gets real close to me and asks me whats wrong. I spill out all my feelings about how the rumors weren't true and how much I like him. I started to cry.. and then he pulls my arms around him and says "Give me a hug" and then me being the weirdo that I am, I tell him he smells good and he just smiles. I thought everything was fine. I was wrong. He then when on a date with a different girl, then dated someone else, and is always talking about girls in his facebook status (like "Ohh gosh hitting on a girl and then finding out she's in a relationship yikes" or "Worst feeling in world when your.talking to a girl and you might date then she dates someone else the next day" *Note these were copy and pasted*) I still feel horrible and I just can't get over him. He was in my dream last night and I cried when I woke up. I really need advice. Please help me :( :(