If you are subsisting only your daily calorie allotment on junk foods, I can totally see how and why you are starving.
When your diet is filled with wholesome food, you will find that it is easier to get full and stay full yet stay in your range. For example, huge salad topped with protein will make you feel like you ate a ton yet not actually be over 500 calories total, where as the same amount in junk food can be double that or more.
Until you can make it to the store, can you eat the calorie range to maintain your weight? Because, you know, not gaining is still a win.