It’s never too good to lose so much of weight in just one and half months. The ideal aim should be to lose about half kg per week or two kg in a month. Some can effortlessly lose about 3 kg in a month. Too fast weight loss can cause rebound weight gain. Also, it can cause other problems such as loose skin, flabs at unwanted places etc. Apart from losing weight, you need to tone up the body. A combination of aerobic, strength training and stretches works best. Many people find it difficult to fit an exercise regimen into their lives. The best way is to join a nutrition expert and a physical trainer (or a gym) and follow their advice. Incorporating yoga into this regimen takes stress out of this exercise to lose weight. Also the diet should contain more of green leafy vegetables, fruits and protein and less of spaghetti, potato etc. I suggest you eat frequent small meals and stop counting calories. It is best to eat lots of fruits and non-starchy green veggies, go slow on fats, eat carbohydrates in moderation and increase your protein intake (lean cuts, whites of eggs etc). Drink plenty of water and non fattening fluids such as clear soups etc. Look for hidden calories in salads and soups and avoid them (eg: cheese, butter, dressings etc). Hope this helps. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.