Re: Terminating apartment contract early.
Post 2
I'm not a specialist here but it seems pretty straightforward: your contract is a legal document and it specifies the terms and when you can legally leave. This depends a bit on the contract, the usual situation is that during the first year you're not allowed to leave, and then there are official dates (3 per year I think) where you can leave, but only with 3 months notice. Other contracts are made for several years and you cannot break them.
The only way out is, as you said, finding a tenant. Now I don't want to scare you but you are a bit late for this. Most regies (the big ones anyway) ask that you send them a letter to terminate the contract at least one month before the desired date. It's true that legally you are obliged to present one tenant who is ready to take over your contract as it is. Beware: if this person ends up not to have the required papers or in the end doesn't want to take over the flat after all, it's your problem, which means you have to find another person. If the regie refuses them for other (personal) reasons, it's not your problem.
So, to sum up: if you don't terminate the contract legally, and you're not able to continue to pay the rent, you might be in big trouble. And also, tell your regie quickly that you're leaving (maybe even before you have found a tenant).
If you read french, you might also find some answers on http://asloca.ch/
P.S. We're trying to find an apartment as soon as possible - let me know the details about yours, we might be able to help you out there... ;-)