Dreams speak to us in symbols....You could try telling her that you are actually feeling very insecure about your ability to provide her with the things she deserves and this is what is showing up in your dreams.....that you don't feel you have enough to offer her as a husband....that you feel unworthy of her love because SHE is so beautiful a lady. Tell her that you feel she worthy of someone better than you. Put it to her, that the mistake you speak of while dreaming is not that you don't love her enough to stay, but that you love her so much that you put her happiness above yours......if you do indeed love her, then this interpretation of your dreams is probably closer to the truth than the interpretation she is hearing - i.e. that you don't love her and wish you hadn't married her.
Let us know how she responds
Sue. P.