I hear ya man. Its possible, especially starting young. What i would suggest is something like this. 3 Solid meals, and two Real Gains shakes. Its all you can do right now.
Have a nice big breakfast(before work), lunch(inbetween shifts after training), and dinner(after work). During work have a shaker with Real Gains powder in it, go to the bathroom at about half way through your shift and add water, or milk if you can get some, and drink it. Itll take 2 mins and noone will know, nor will they care. Do the same thing for both shifts!