Then Love Came Along - S2.E19

Roger Hamilton had gone through life with more money and power than he could ever have dreamed of as a child, but when a transaction goes sour and he ends up dead he gets his second chance.

Roger is returned to his youth as a doctor who has to make the decision of who to give a kidney trasplant to. He meets Caroline and her newphew Mikey, and falls in love.

On the way out of a jewelry shop (with a ring) Roger is injured and they discover his kidney isn't working properly.

Roger must then decide whether to give the available kidney to his younger self - or sacrifice himself for Caroline.