University classes

I'm studying in medical technology school. And my classmates and I have classes from monday to saturday. We are studying from 7 am to 7 pm, and usually we are tired and sleepy in class*, because we go to sleep very late because of all the homework and studying we have to do. I am sacrificing a lot of time for my career but i love it, and all my effort will be worth it when I graduate and achieve my dream..

entiendo que tienes muchas clases, y estás cansada en todas, pero en más natural decir simplemente "class" y entendimos  que se refiere a todas.

o otro modo: we are usually tired and sleepy in our classes, pero el arriba es mejor

University classes

I'm study in Medical faculty, in medical technology school. And my classmates and I have classes from monday to saturday, we are studying from 7 am to 7 pm, and we are usually tired and sleepy in classes, because we sleep very late to do our homework and study lessons, my career is very sacrificed, but i love it (you don't need to repeat "career"), and all effort is great when my dream is graduate.