Here's my mushy story that I NEED HELP WITH?

I tooootally like this guy and I'm gonna shorten the story as much as possible. We went on a blind date set up by my friend last summer (thats the first time we met). Got pretty friendly, then I stopped talking to him. Then at school, he dated my friend, and I got jealous, but didn't do anything about it. Then they broke up and he "accidentally" texted me and we became really good friends since then. He asked me out, and I said no because I didn't want to date him. I also told him that part. We stayed really good friends, hung once, it was really really fun. I thought the realtionship was elevating and I thought maybe it wouldn't hurt to try again (the dating thing). But then he went to Sadies (school dance) with this girl, and they'v been dating ever since and I'm SO LOVESICK. I am jealous, and he's been in my dreams more and more, and I txtd him a couple times, he doesn't wanna hang (even though he says we will, i can tell he doesn't wanna). And it's just been awkward AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH I'm not even sure of my question, I just had to vent. Well actually wait, I do have a question. I know I can't do anything considering he's dating and I'm not a backstabber cheater person, but what CAN I do?