I beleive nothing happened to the Giver, but when Rosemary was released everyone in the community got the memories. The memories of pain,war,love,and suffering , but since the Giver already had these memories he did not suffer unlike the rest of the community.
The Giver stays in the Community, after Jonas leaves with Gabriel. The Giver helps the Community deal with all of the new memories and feelings they have received, because when Jonas left, all the memories he got from The Giver were released into the Community.
Because when she was "released" all the memories that the Giver had given to her were brought back to the community, they received the memories that Rosemary had been given. The whole community had received the memories.
Jonas gives people memories by running away so they can all go back to the community- for memories are forever. once he got memories, he has the ability to give them away to. he just followed what the giver did and gave some memories to Gabe.
The Giver transmitted memories by placing his hands on Jonas' shoulders and then transmitting them. NOTE!: I believe that the only people who could receive memories were the ones with pale eyes....Jonas could give memories to Gabriel, but not Asher or Lily.
The Receiver in the community holds the memories of all the community (sad, happy...etc.). And the memories are from generations way before Jonas's. The Giver is the one who passes the memories to Jonas.
Once Jonas would leave the community all his memories would come back to the community and everyone would have his painful memories. The Giver would need to be there to help treat everyone from the memories. After that the Giver was going to die so he could be with his daughter, Rosemary.
The Giver transmits memories, some bad some good, to Jonas. He prepares him for his assignment which is, The Receiver. The receiver receives all the bad memories from the town so the town is not sad. "It is better for one to suffer than all to suffer", The Giver.
because the person who gives Jonas the memories used to be the receiver of memory but since Jonas is the new receiver of memory, the old receiver of memory calls himself the giver because he GIVES the memories