How do I motivate myself to go to school?

I have been going rarely lately because I've been sick but I guess I've used my health as an excuse because I could go but I dread it so much that I convince myself I'm sicker then I really am. How do I motivate myself? My mum doesn't really push me to go because I'm ' sick ' and I'm starting to fail my final years. I'm in year 11 and In Australia we do VCE which by doing that you can go to university ( college in other countries I think ) and I've always been that type of girl who knows her future, wants the best and I've always said I'm going to finish year 12 and go to uni. But now I want to drop out. I know I'll probably regret it if I do and I'll get judged so much by other people but that's how much I'm dreading school. And I'm not getting bullied or anything and I don't know why this is happening. What do I do?