It's Crucifixion (being fixed to a cross). Why do you put the word 'fiction' in there?
...why then must Christ be sacrificed repeatedly thousands of times per day for thousands of years?
Because He said so.
...and who are we to thrust His sacrifice upon Him again and again?
We are the ones whom He asked to do so.
To be more specific, the Sacrifice of the Eucharist IS the Sacrifice of the Cross. They are one and the same. The Sacrifice has eternal effects. It isn't "over and over."
So I can't spell.
Scripture is clear that Christ's sacrifice was a one-time event. We were directed to remember it, not repeat it.