You THINK you have Christ for communion, but Christ was only sacrificed on the cross one time and that was sufficient for our sins (Acts 4:12; Hebrews 10:14). Christ is not re-sacrificed every time Catholics have a mass.
You wrote:
“Christ is not re-sacrificed every time Catholics have a mass.”
Of course not. The one sacrifice was enough and it is exactly that sacrifice which is re-presented to the Father at every Mass.