Dealing with the cost of supplements and food can be hard at times. Best thing to do is figure out what will cost you less. You can get your macros from such supplements as weight gainers/whey protein, but if possible, whole foods are a much better choice imo.

Regardless, try and boost your caloric intake as much as possible. You're definitely gunna have to eat to grow! Keep at it, with the right motivation and determination, anything is possible.
Best of luck.