OK. How did God make man?
Simple. Unlike transubstantiation, God created man,
out of nothing,
with a body of flesh and blood,
that remained fully flesh and blood in substance, not having any other substance,
and that could only be in one place at one time,
and that could not give spiritual qualities to anyone by eating it, nor was eating it a requirement or manifestly sanctioned,
and which housed a soul and a spirit, which transcend the body and can exist separate from it.
Thus you have no argument by analogy. Your only argument for this unique act of transubstantiation is that God can do anything, but it remains that this has no correspondence to any other miracle in Scripture, as Catholic theologians can tell you.
Nor is the theology of eating human flesh and or blood, or anything physical, to gain spiritual life consistent with Scripture, nor that of a separate class of believers distinctively entitled "priests"offering the Lord's supper as a sacrifice for sins as their primary function, while the language as metaphorical is consistent with Scripture, as is the metaphorical interpretation. And which is the only one that is!
Give it up.