Ok so seriously...
You want to eat helthy, but you need to eat more, so as someone else suggested, eat 4 meals a day, i suggest not snacking tho, and eating bigger meals.
So 4 big meals a day, which are well balanced in nutrition, eat more steak and fish.
The problem you probably have at the moment, is you are burning more calories in a day than you are eating, thus no gain in weight..
i eat 4 meals a day (not overly big ones) but i snack as well, and i have in the past gained a stone in 3 months. so not bad, and it's good for you.