I was bought an olive tree in a planter as a present. It is lollipop shaped and I have had it about five months. The card on it suggested that it come indoors for winter as it would not survive the frosts. I brought it in in October and suddenly all the leaves have started dropping off but not turning yellow first. What on earth am I doing wrong. It is in the kitchen, which is quite cool all year round, and I water it once a week.

Please help me.

Bringing some certain kinds of plants inside after being outside where they where in brighter light and had lots more humidity can cause rapid leaf loss once brought indoors. It needs to get adjusted to the lower light change most likely more than anything else. Try to give your olive tree the same light it was in outdoors. Being in warm dry room vs a cooler room might make things worse. Let the soil get close to dry before watering, You don't want to over-water it now that it has a lot less leaves, hopefully with the right care, new leaves will grow back. Don't fertilize now until you see lots of new growth in the spring/summer months.