If you want to just focus on a few verses you get bad theology.
Then Jesus beholding him loved him, and said to him, One thing you lack: go your way, sell whatever you have, and give to the poor, and you shall have treasure in heaven: and come, take up the cross, and follow me. Mark 10:21
Have you sold all of your possessions?
Have you plucked your eyes out as noted in Mark 9:47?
If the catholic believes in a true literal understanding of John 6:53-59 they will also do these things.
That catholics don't do this is telling.
You said Jesus would never say/command his disciples to drink His blood. Your Bible says otherwise.
End of discussion.
Christ sometimes speaks literally, and sometimes He uses metaphor and parables.
Was He speaking metaphorically when He commanded His disciples to eat His body and drink His blood?
No, He meant His words to be taken literally.
How do we know this? I can think of two reasons, though I don't doubt that there are others:
a) As well as speaking of His Body and Blood in Capernaum, Christ instituted the Eucharist at the Last Supper.
And He took the bread, gave thanks and broke it, and gave to them, saying, "This is My body, given for you; do this in remembrance of Me."
St Paul corroborates the true nature of the Eucharist in several passages. For instance:
When we bless the cup at the Lord's Table, aren't we sharing in the blood of Christ? And when we break the bread, aren't we sharing in the body of Christ?
And also:
For those who eat and drink without discerning the body of Christ eat and drink judgment on themselves.
b) When Christ told his disciples that they must eat His body and drink His blood, many of them left Him.
If Christ was speaking metaphorically, why did they leave Him?
If they simply misunderstood His words, then why didn't Christ call them back to explain what He really meant?
Hope this proves helpful.