sounds exactly like the tracking is out, the two wheels are probably pointing very slighty towards the outside of the car on their sides, teh feeling of driving on ice is because the wheels are going different directions they are ruining each others grip by pulling against eachother. get it to a garage as soon as you can cause your tyres will be needing replaced too if you drive much like this as it wears away rubber like crazy.
id be 99% sure that that is what it is. should be fairly cheap to fix, £25-30 for labour and no parts or rising steeply to about £250-300 if you need tyres. a stitch in time...
2.0 TS, custom hand stitched leather and alacantra interior, custom SS system, H+R suspension upgrade