Advices needed, how do I move past this diet plateau??

Hi, this is the first time I post on this forum, so I'm not exactly sure if this is the correct place to post. If not, please let me know, Thanks.

I'm 23 yrs old and 5''3, originally weighted at 140 lbs. Prior to my diet, I generally don't exercise, and eat rather unhealthily.

After I decided to get on a diet, I read a few articles online and decided that I will follow a calorie-reduced diet, accompnany by some cardio exercise. Due to my current super busy schedule, i'm only able to do about 1.5 hrs of cardio every week. (treadmill, 5mph). My plan was after I finish with my super busy period, I will join a gym and get some professional advice starting in Nov.

As for my diet, I'm following a strictly 1200 cal/day diet. I measure everything from food to condiments I used in cooking, so I'm quite positive that they are accurate.

So I'm on my diet for threes already, results were pretty good for the first couple weeks, I lost nearly 10 lbs, and starting last week, the drop in weight gets slower but I thought it was totally normal. Until about three days ago, during my usual morning weighting, I realized that my weight stops dropping altogether. Now it's been on the exactly same number three days in a roll, that's why I felt like i've hit a plateau in my diet.

I read many articles online about dealing with plateau, and most of them suggest either reduce calorie intake, or increase exercise time. My problem right now is, i'm already at 1200 cal daily minimum, so I'm not sure if it's healthy to further reduce my food intake. I also dont have extra time to exercise in the next two months.

I also read the Curves book, and there was a suggestion to deal with plateau in there, called metabolic tune-up. the basic idea behind it is that, the reason you hit plateau is because ur body's metabolism is decreasing, so you need to increase it before you can further lose weight. and the plan goes as follows:

1. resume a 2500 cal, regular food intake, until you gain 3-5 lbs.
2. go back to an 1200 cal diet for 1-3 days and you should lose that 3-5 lbs fast, do not stay at the 1200 cal diet for longer than 3 days.
3. repeat step 1&2

The book explains that the time it takes to gain that extra 3 lbs on a 2500 plan will take longer and longer because ur body's metabolism is catching up, so eventually you will be eating at 2500cal for a month and not gaining any weight. At that point you can go back to your original diet (whatever it is), and your plateau will be gone.

The book made a pretty good argument, however I was a little hesitated because it felt a bit unhealthy to alternate food intake so rapidly within a short period of time? but I am no expert on this, so I really would like to get some opinion on this metabolic tune up plan.

Again I would really like to hear any advice on how to deal with my plateau situation. Thanks a lot.