I no longer want to be the funny fat friend. I wanna be the funny HOT friend!

I love who I am, but I would love to have more energy. I'm currently at 210 lbs. Getting down to 150 would be great, but I really just want to feel good. I would really like to be a size 12 as I am currently a size 16-18. I just need the motivation. I've started to ride my bike to work at least one day a week (10 miles round trip) and I am very active at work, but I need to push myself more. I need to quit making excuses and get my butt on that bike more often. It's a good start!
I'm going to start the Zumba DVDs here soon and I'm going to get back on the South Beach diet. I had some luck with it a few years back and I really enjoyed it. I would really appreciate any advice on how to get motivated. That's the hardest part! It feels good just being on this forum, so I've at least started something!