First off you need to start reading and researching about such things as diet and training. And I dont mean just here on this site.
Second, If you dont eat, you cant grow, so you have to sort out your diet issues. At this point (not sure of your age) at your weight, you simply are not eating anywhere near enough to gain. Is there some physical problem that hurts your appetite? And focus on real food, not supplements and pwoders and pills. The only thing you might want to look into is a whey protein shake or possibly a mass builder. But this is in addition to real food, not a substitute.
Third, you must get into the gym. Dont have time is a poor excuse. You have to make time 3-4 times a week. So start looking into beginners routines. Dont get caught up into which bodypart and when or split routines - just start looking into the basic mass buiding exercises for each bodypart, learn how to do them and look to build strength slowly. With proper nutrition, gains will come.
Fourth, FORGET about steroids- they are not your answer and not magic. you are nowhere near ready.