I think it's important to have reachable goals, so instead of saying that 68kgs is your goal weight and you are currently 99kgs, rather say that 95 is your short term goal and work from there. Also, taking photos of yourself as the fat melts away is important for motivation. Stick them on the refrigerator, or on your cupboards in the kitchen where you can see how much is actually coming off.
My motivation was born out of not being able to find anything to wear that looked good on me. Buying new clothes was not a treat because I looked like a lump in everything. Then one day, my husband said that if I could lose weight and get down to a size 10, he would buy me a lovely outfit no matter what the cost. I was a size 16/18. It was not so much the fact that he was going to buy me a new outfit, but it was the motivation behind it. eg, you are unhappy the way you are, and so let me help you do something about it. Look, here's a carrot! I'm down to a size 12 now, with just a bit more than 8kgs to go, which I hope to reach before August this year (coz I started dieting in August last year). It's going slow even though I rarely cheat, and do lots of exercise and drink lots of water, but apparently the slower the weight comes off the better, so I'm going to stop moaning about that soon.
Anyway, good luck! And remember that we are all in the same boat in one way or another, so you will find plenty of support on this forum.
SW: 76kg (08/07)
CW: 60.2kg (21/05)