49.5% She's bored with you.
49.5% She has her eyes on someone else
1% She's not a lying bitch.

I know you're going to hang onto that 1%, but I wouldn't if I were you. I was serious with one girl during high school. I thought it was love, and I always think long term on everything. I started wondering, "If everything goes as I dream it will... will I even want this?" That could be how she's thinking now, but I doubt it. And Jessifer stop your damn lying!

Good Luck, but definitely don't mope around and make yourself look like a loser. That'll make things 100% worse.