Why are they sooo expensive!!!

Ounce you live alone you notice how expensive everything is. I never knew groceries are so expensive. Ive lived alone for a long time now. The first two and a half years I lived in my stepdad"s condominium so I didn't have to pay rent. I was not occupied anyways so I stayed there for free. Plus living alone doesn't really cost that much. Since I don't really eat a lot I barely had to make trips to the grocery store. Life was good. Now I have been living with my boyfriend for over a year and a half. It hasnt been easy. I work full time and there still is never enough money. I have no idea what to do anymore. I cant get another job because I already have work full time and school full time, there is just not enough time in the day. Hopefully the summer will come soon and Ill be able to save some money while school is out. Another thing that is increadebly expencive are the books!! Ive spend over 600 dollars on ooks alove this semester. Why are they sooo expesive!!