What should I do to get stronger and faster for next year.?

I'm currently a sopre and next year going to be a junior. I a defensive end. I'm 6'0 182 pounds. During the football season I didn't lift much, so I'm basically back to square 1. I desperately need to get stronger and faster. My defensive end coach told me I need to get faster, and my head coach told me to get stronger and not worry about speed. I'm so confused. I'm trying to lift every day and I'm using a protein powder called pro complex, if that matters all. Also after each workout I eat a baked potato and meat. I joined indoor track, but i Absolutely it. I'm a sprinter. I know I'll get stronger and faster by running track and lifting after but I don't understand the process of so much preparation a ten second race. I'm use to this much preparation a long event like a football or basketball game. Can anyone give me advice on how to get bigger and or faster. i'm in the running to start on defensive for the varsity so I need to get better. Also grades aren't an issue.