Nerd to loose 100 lbs.

I've only lost 5 so far. I'm 5'1" and started at 198. "Ideal weight" would have me around 105-115. I CANNOT imagine getting to that place. I think 135-140 is probably something I could maintain..but honestly, I've never really "TRIED" to get lower than that. So regardless...I have 60-80 lbs to lose myself. Oh, and I'm 44.