How not to get pancaked in (american) football?

I'm a linemen in football, and I get pancaked at least once or twice every two weeks by the varsity players (I usually do have a pretty good stance and do all of my steps) and it's embarrassing because no one else my age does get pancaked, with an acception of 4 or 5 times. But my question is How do I stop getting pancaked? And how can I pancake block more people?