Agreed with the expert above!
If you want to lose 30 pounds in 4 months that equals almost 2 lbs a week.. which is not really recommended. I believe it is 1-1.5lbs a week which is healthy to loose but...
If you stick with a healthy diet and exercise regime I'm sure you can do this, or at least get close to the 130 for your prom. You will feel GREAT!
Best of luck
What you need to do is eliminate the common causes of increase in weight such as overeating, lack of exercise, diabetes, and hypothyroidism. Anemia, low proteins, adrenal gland problems, kidney and liver problems and Cushing Syndrome has to be eliminated. Late night snacking and poor sleep patterns too cause weight gain. Certain medications like antidepressants cause weight gain. Polycystic ovary too causes weight gain, hence has to be ruled out by an ultrasound of abdomen.
If the above causes are eliminated then you can join a weight trainer and a nutrition expert and follow their advice and lose weight under their guidance.
Take up yoga, deep breathing exercise, walking and remain strong and determined in your effort to do away with this habit. Music and aerobics are also good stress busters. Also the diet should contain more of green leafy vegetables, fruits and protein and less of spaghetti, potato etc. Take care!