No, you're right Tom, if you're only loving her because it makes you happy but do you love her 'selflessly'? Doesn't sound like it - Sounds like you love her to make you happy. To love someone unconditionally is to truly love them. You cannot weigh someone else's value of love based on your own selfish way of loving.
Some people truly do love to the highest value. Yes, it is possible to love someone greater than your own needs and wants - that's the purest definition of love and the rarest form to be found.
Commitment to that kind of love comes only because of the love, to honour it and cherish it.
Of course we want it reciprocated and we want to feel their love in return but it doesn't always happen. If your wife didn't respond in the expected manner, would you still Continue to love her or would you love her because you had no choice, you just had to love her because of who she is - without reward, without reciprocation?
Some people in this life get to experience a truly selfless form of love, a love that stays simply because there is no other choice whether together or apart, a love that they give purely and without anything in return, a love that is rare, a love that is unconditional.