Theodore would spend every moment of this life atoning for his past one. His engagement and marriage to you were all arranged, devoid of any love. But you tried, you tried really hard to love him and what did he do? Theodore brought in a mistress. He'd been blinded by greed and caused you so much pain.
He'd neglected you and pushed you aside, leaving you on your own with no one on your side as his mistress lavishly spent his money. It was only when Theodore saw your cold lifeless body after being murdered by his mistress did he realize what he'd done. As he clung to your body, sobbing out for you, he wished he could do it all over again.
Now here he was, 10 years in the past to when he and you were just engaged, not a clue as to how he went back in time. Mark his words.
Theodore would love you the way you deserved the first time. Obsessively so.