Concentration and effort level

After pitching my first season at the varsity level for a good prep school, i finally found out my biggest problem. I lower myself to bad teams and dont concentrate as much thinking they aren’t goin to beat me anyway. But when im on the hill to start a big game, i get real pumped up and let it all loose and am almost to focused. Example: last year i started the biggest game of the reg. season friday night on the road in my hometown and a hectic environment. I pitched out of trouble in the 1st two innings giving up no runs. I got 2 quick outs in the 3rd then got leg cramps…trainer and coach came out and i kept myself in the game a walk and a homer later i was walkin off the mound trailing 2-0 with 2 outs in the 3rd…anybody kno how i can stay concentrated equally for all starts?

i was a sophmore last season.