Hi, I'm in much the same position as you. There are a few Masters courses in English at ETH (
http://www.ethz.ch/prospectives/programmes/index_EN) but none of them were what I wanted.
Through friends who teach at these places I know there are also courses at St Gallen University and the University of Zurich that are taught in English, but I'm not sure that they are 100% English and I haven't found anything I really want to do.
In the end, I've decided to do something online from an Australian university, as I'm Australian and therefore still classed as a domestic student there. Otherwise, there's the Open University in the UK (way too expensive for me as I'd be classed as an International student) or all the business schools here, but they're pretty expensive, too.
If you know exactly which areas of study you're interested in I think it could be worth just contacting the relevant departments and asking them, as there does seem to be a lot going on in English. Alternatively, you could perhaps audit some of the courses to see what you think and and at least that would get you in a studying frame of mind again.
Hope that helps!
Kate