"And when He gave the Bread of Life discourse and when He instituted the Eucarist, He was doing what He said He was doing"
This won't be the first time that I appear obtuse but I still don't understand why it was necessary for Jesus to eat His own flesh and drink His own blood at the Lord's Supper. He said to the disciples that if they did not participate they had no part in Him and yet He participated in the same supper. It seems more logical that this was a memorial meal and He was the host rather than the main course, and I don't mean that to be sarcasm.
He was instituting the priesthood, and this is what priests do.
Jesus had no "need" to partake of His Body and Blood, that's for sure. He also had no "need" of baptism, yet He submitted Himself to that as well. We are to live in imitation of Him, and He wanted to experience humanity in its fullness. That included the sacraments.
SD