You could make a frozen yoghurt, there are plenty of varieties of low fat, no sugar yoghurts, which you could freeze in a shallow metal tray, take out of the freezer every half an hour or so, beat, and then put back again.
Icecream can be made two ways, with either cream (not an option for you) or a custard base. A low fat custard made with custard powder and splenda should do the trick, then follow above method, freezing in a shallow metal tray and beating regularly. It's not going to be the same as bought ice cream, but that's the point of making it at home!
I know there are diabetic friendly icecreams in Oz, I am originally an Australian, and my mum and dad are both diabetics now. There is one made by Peters, I think, that comes in squares individually wrapped. There are probably loads of others, it's been a long time since I was at an Aussie supermarket.
Consider getting an icecream maker, they aren't too expensive, and in a few months you'll be able to pick one up in the sales!