Want to gain weight. Stuffs like that.

I eat quite well but still not able to gain weight ,tell me what and when to eat ,full routine and also i cant afford costly food products and medicines hence try to make  routine consisting of foods which are available in every ones kitchen,every middle class family. I also have noticed that if i dont eat properly for one day due to some outdoor works,i would start to look more skiny on that day even the area near my eyes would become a lil darker and if i walk or stand for some time my back ie spine will ache terribly,so much that it will be difficult for me to stand straight .If i eat regularly it wont have any effect on my body buy just one day without having proper meal and i will start feeling very weak and skinny .Help me with a time table saying what to eat at what time and how much water i should drink daily,keeping in mind my back problem and i gave also noticed that my hands shiver when i try to take selfie or stuffs like that.