HELP! i think duromine has stopped working

Hi guys im onto my second week using 30 mg duromine. The first week was great, i had so much energy, wasnt hungry but ate 4 small healthy meals, drank 4ltrs of water and exercised twice a day for 40 minutes (cardio mainly) I lost 7.6 kg in 7 days... Now this week I am doing everything exactly the same and I'm not seeing any results at all. If anything I'm getting hungry and I don't have that fantastic energy I had last week. I'm 6'3" tall and I weigh 120.6kg now.. My Goal is to lose another 13kg. I have a lot of friends who go to the gym and they told me I needed to take a break for a day and eat a few carbs so my body doesn't go into 'starvation' mode. I did that yesterday and I feel a lot better today with my energy.. I just want to know if anyone else has had a similar experience? :/ what advice do you have so I can continue to lose the weight?