Long term nutritional intake is indeed important, but for most people, a short term 'deficit' in nutrition will not kill them. In other words, what is currently available for you to eat is not as important as how MUCH OF IT you are eating. You can still eat crap and get in better shape. Don't believe me? Look up the twinkie diet. Wait, I'll find it for you:
Twinkie diet helps nutrition professor lose 27 pounds - CNN.com
Now, again short term eating like crap is not horrible and will not shorten your life. So, given that you expect to have better nutritional options in the semi-near future, don't worry so much about 'what' you are eating and worry more over actual caloric totals. Most people should not consume more than 1700-2000 calories total per day. Most people on average, eat most of their calories at night. That's probably the biggest dietary mistake you can make. The metabolism begins to slow after the afternoon hours. You can eat a small breakfast, a bigger lunch and then a massive dinner and even if your calories are no more than 2,000 for the day, you can still be fighting an uphill battle. Even if you are exercising enough to create a caloric deficit where you are burning more calories than you consume. You should eat the opposite of how most people do if you want to lose weight. Your biggest meal being in the morning (you've just fasted all night for 6-10 hours of sleep), a smaller meal for lunch and the smallest meal at night.
There's more to read online, but I'll leave that up to you since you're serious about it.