Welcome to the forums! It's nice to see that you're making a commitment to changing your life by losing weight however, I do have some concerns for the way that you are attempting to do it. I'm sure a few other girls on here can give you more info, but just personally - are you sure that you can eat only 500 calories a day for the rest of your life? Because while it may work in the short run, in the long run you're likely to put all that weight back on and some because you simply cannot stick to that strict of a diet. Apparently the slower you lose the weight, the more likely you are to keep it off in the long run. Even very low calorie diets (like slimfast etc) recommend that you have about 800 calories a day but that you only do it for 12 weeks because of health risks - at that point you need to wean yourself onto a proper 1200 - 2000 calorie diet (depending on your weight at the time). I currently weigh 127kgs (just like where you started), and using calorieking I know that I can eat about 2100 calories a day and by going to the gym and stuff I'm losing it very slowly, but I know that I'm going to keep it off!
I wish you all the best of luck at changing your lifestyle and losing that weight and I really hope you do - but I hope you don't do it at the expense of your health.
Good luck hun,