My poop is mostly broken, cracked and in small pieces. I am not having normal I.e sausage shapes silky poop for months why?

Diet change . The most common thing to cause changes in what comes out is a change in what goes in. It could be intentional or just because of changes in your schedule, travel, or the season but the amount and type of liquids and fiber you are consuming makes a huge difference in your bowel movements. At 19 this is probably all that is going on. Worry if they change color or you notice blood. Hope this helps.