Having worked in a similiar environment, I have experienced a lot of what you are going through right now. Like Keith said, a lot of managers feel that it’s ok to tell their staff that they are just a cog in the machine and give a “if you don’t like it, leave” attitude. If you stay in that environment for long enough, eventually you will believe in the lies they tell you and this will have a collapsing effect into the other areas of your life.

My suggestion: start looking for something else because it’s not worth spending the bulk of your time at a place that under values your input.