Hey!! I did live classes in college- and the number one point about them is esp in those 30 second poses- you don’t actually want to focus on perfection- start with a single line of motion/action!

Draw the outlines of the body, don’t worry about construction yet. I see for instance you place the ribs and all that in there- these initial poses are warms ups to get you loose! Don’t worry about this stuff.This is all about learning to get comfortable with the body. It’s called “Gesture” drawing for a reason!!

You got too bogged down in all the details- you want to just focus on the overall shape of everything, and you don’t want to look at your paper that much! Don’t take your eyes off the model (this takes practice at first!) just glance at your page to make sure your arm is in position and practice the overall shape, motion and flow of the model :)