How does this descriptive paragraph sound?

As I'm sitting in the uncomfortable blue chairs, the teacher begins to call on students. I look up at the clock, and hope the teacher isn't going to call on me. "Thank God" I sigh as I begin to look around the empty once white wall. I continued to look and begin to think of the medium rare steak dinner my dad is fixing, and how in only 32 more minutes, I will be free. I glance up for at the white board and see faded red numbers, I jot the numbers on my bare college-ruled notebook. The next 32 minutes of lecture seem almost unbearable. I glance down at my white iphone and notice that there's only 20 minutes left. "Yes" I mumble under my breathe, as I begin to put my black sweater on. I look back up at whiteboard and notice some type of weird God-forsaken equation written, I wrote the equation perfect, yet have no idea of it's meaning. I begin to draw on my number filled paper, hoping that this will help the time go by faster. Suddenly, the bells rings, and I'm the first one out the door.

Its really good at the moment, however, use more descriptive words. For example, instead of just saying 'white' pick a specific shade or a similie or something. Although this is supposed to be descriptive, just remember to not got to overboard or it can sound a bit awkward x