At least you've worked out early on that refined sugar may be an issue for you - and now you can take steps to avoid it as much as possible. I agree with the suggeestions and advice EWQ gave you, low GI foods are an excellent idea, and she has explained the effects they will have on your body well.
Don't worry too much about your weightloss at the moment - you lost 0.5kgs and that's great! See how you go over the next 2-3 weeks, and track your losses. It's too early to tell if you're plateauing already
If you're not satisfied with your results after a month or so, maybe post a sample of your diet up here, and let people offer you some constructive feedback and advice, and see if they believe there is anyway to improve it!
I know from personal experience that often we think we're making healthy choices and in reality, we're not. For example: I used to drink fruit juice ALL the time, glasses of it daily. I thought I was being healthy because it was from fruit and was natural, but what I didn't realise was that there was just as much sugar in a glass of juice as there was in a glass of coke. Now I'm more careful and only drink one glass of juice a day with breakfast, because I don't want the unnecessary calories. Little things like that can make a big difference. I think there's perhaps 200cals or so in a glass of juice... so imagine what I was doing to my diet when I used to drink maybe 3-4 glasses a day!
Best of luck for this week's weigh in