Also, make sure you're drinking enough water and getting enough sleep. Those are two things that fall by the wayside as you're trying to fit everything in and learn everything you need to know. Those two things can also affect your weight. One thing I try to do is find excuses to have a little more activity throughout the day - little things, like parking farther away, taking stairs instead of the elevator, getting up and stretching and maybe doing a few little exercises, taking a quick walk, etc. I need to incorporate more structured exercise, but getting more activity in when you're time crunched can be difficult. Sometimes you have to be really creative. lol
Sometimes it can seem overwhelming to totally change what you're eating. What you can do then is to change one thing at a time. Maybe first you could drink half the amount of soda/juice/drinks with calories and substitute the rest with water. Once you've done that for a bit, you can make another change, like make it a goal to eat a cereal with 3 or more grams of fiber for breakfast, while still maintaining other changes. Then, make a goal to eat a certain number of servings of fruits and vegetables each day, and so on. When it's gradual, it ends up being easier to maintain, and more likely to become a healthy lifestyle change.