Best plan to lose 50 lbs in 6 months

I have lost about 50 pounds in just over a year and i started out by commiting to 30 minutes of physical activity daily, whether it be walking, running, a work out video, anything that got me moving. After a month, it became not only a habit but an addiction and so i began writing down everything I eat. I have a little formula i use to calculate a daily deficit. I should eat about 2,000 calories to maintain 138 lbs., so i take my daily caloric intake (usually about 1575) and subtract it from 2,000 and then add on my daily calorie burn, so if i ran for 30 minutes that would be 320 calories burned so my daily deficit would be 2000-1575=425+320=745. I make a cumulative total for the week and aim for a total deficit of 3,500 or greater for the week because they say 3,500 calories is a pound. caloriesperhour.com has some good free calculators for calories burned as well as BMR and RMR calculators to help you figure out what your daily caloric intake should be. I still eat fast food occassionally and candy and chips, i just write it down and adjust the rest of my meals when i do eat bad. I don't think weight loss needs to be about cutting things completely out of your life, but about making smart decisions most of the time. I usually eat my 5 veggies and 4 fruits a day and i make sure i eat 48 grams of whole grains a day and at least 25 grams of fiber a day and i drink LOTS of water, but when you declare a food completely off limits, then you are setting yourself up for stress and guilt. I tried being a vegetarian for the past 3 months, but i have been feeling really tired and worn out and it's because i haven't been getting enough protein. If you go to mypyramid.gov you can enter in a typical day of meals in a food log and it will tell you what areas you are lacking in vitamins and such. Most things i have read recommend a diet of 40% carbs, 30% protein and 30% fats for ideal body function. I don't typically figure this out on a daily basis, but every few weeks i calculate a day's worth of meals and see if i am on the right track. As someone who is only 6 pounds away from my ideal body, i have to say the hardest part is starting out. Once you make the decision and are truley committed, it's not so bad