Sex with your wife for reasons other than begotting children is lust, not love. The reason you believe differently is because you haven't realized what Srila Prabhupadas point is.

The same thing with eating garlic and onions, as well as taking caffeinnated beverages or foodstuffs.

You can take my life for example if you want. I used to eat all kinds of stuff (no meat, but I did eat eggs). I ate tons of chocolate, drank chai (Indian coffee) since childhood. I listened to all sorts of music, from rap to hardcore rock; watched all kinds of cinemas (and I do mean all kinds).

Yet, because of Prabhupada's books(and some others), I can see very clearly why those things are detremental to a human being. I don't listen to any other kinds of music other than bhajans nowadays. I have lost most, if not all, taste for TV and movies. I no longer have a desire to eat outside food, and for the record, my addiction to Taco Bell is popular in my family.

My life is a whole lot better because I gave up all those things. Looking back, I couldn't believe I was addicted to such nonsense.

My advice is to do some research. Prabhupadas books are very confusing to read if you don't understand his line of thought. You're not alone in this, I had the same problem, and I can understand very well what your position is on this matter, for I to did not think I could give up sex, chocolate, video games, and anything else.