You can be 'addicted' to anything at all coffee, crack, masturbation

, sunsets, beach, blondes, billiars and....bananas! haha but it's not whatever one is addicted to that is the real problem, it's what is going on in your mind that is allowing you to let go of self control.
As for fruits, or any sugar concentrating food must be eaten in moderate quantities only, and this will vary from person to person. The important thing is to learn to really listen to your body because it is always telling you what it wants and needs and what it doesn't. Even if you're not perceiving the signals, or recognizing them, they're still there.
I also think Bronwen, that it's sooo cool that you are that open to changing your outlook and are following after truth. It's so rare.
Someone above said that if you're on a high fat diet your wouldn't want to eat lots of sugar or fruits but I would disagree, I'd say that would be the best time to do so. Fat is there to, among other things, protect and insulate the body from toxins and it probably slows down the absorption of sugar in to the blood, moderating the body's need to produce insulin.
Also when trying to determine how much sugar to intake you can consider how much exercise you get.
In any case it's almost certainly risky to bomb your system with sugar. Mainstream medicine says 50 grams of sugar per day per person is a good limit, but mainstream medicine is whacked so it's best to be even more conservative if possible. Above all, listen very carefully to the body.