Fishing Help

I've been fishing small 10-acre lake here in charotte, nc for the past 3 years. It seems that I constantly catch 1-2 lb bass. The largest i ever caught was 3 lbs on a crappie minnow. I usually use plastic worms to fish and they seem to only hit on one side of the lake near the dam. I don't what else to use in this shallow water to help bring in larger fish, I know that they are in there. Please help????? 8)