I need to be healthier

So guys I've had some trouble the past 3 years at

getting back to a healthy weight. I was extremely fit in high school and now I can't even seem to lose enough weight to make me feel better. I try to eat healthy and drink water, also I try and make time to do some small workouts. I drink water a lot, I work as a nurse so that exercise is a good bit but not enough, I honestly don't have time to go to the gym after work, I get home at 11:30 pm, study and do homework and then get maybe 3-5 hours of sleep and go back to school all day and then work. So when I try to eat good it doesn't always work. I have to grab something quick most of the time or I don't eat at all. I need some help!! Someone please tell me something that could work.