As far as size goes, for your weight, ability and riding style a 141-143 seems about right. For carving though a longer board will have more edgehold, and be able to handle speed over the chop.
It actually seems like you've had the right sized board this whole time!
Your feet are small though so waist width should be something in a 22.7-23.0 cm range. There are boards that narrow out there in a 142 or so, or you can have one custom made.