Kanton Zurich has a free service for advising the workers of their rights. The will provide non binding counseling.
It is the Rechtsauskunft des Arbeitsgerichts [Labor Legal Advise] and it is in the Wengistrasse 30, 8004 Zurich. (tram 2, 3 or Bus 32, stop is Kalbreite). Telefon is 044-248 20 62. It is open Monday, Wednesday and Friday, from 8h30 to 11h00 and 13h30 to 16h00. They can take a max of 12 consults every half day. It is not necessary to make an appointment, but you can contact them at tel 044 248 28 45. It seems that the best is to go there and wait patiently for your turn.
Anyway, on a personal note... having walked that road before, I would strongly advise you to take the sick leave until you feel better. Don't take me wrong, but at this point you are not in the best frame of mind to take decisions and you might end up doing something you will regret latter. Being sick is one of the the few when the law actually protects you.
Rest assured you will not have to discuss this with your employer unless you wish to. Sicknesses are considered confidential and within the personal sphere of the employe. All you will have to do is to provide the employer with a paper signed by the doctor that says that you will have to be away to due to "sickness". No questions asked. These sort of illnesses are more frequent than you would imagine and doctors tend to be very sympathetic and helpful with the situation. Really, it is no shame nor stigma in this.
Just make sure your reference letter is kosher and doesn't have coded sentences like "we wish her lots of health in the future".
One last thing - you can be sick and at the same time, eligible to receive RAV subsidy. You are entitled to 60 days of sick pay if memory serves me well. It is better if you are sacked, rather than quit. Technically, they will not be able to fire you due to sickness. Their ground will be more likely to be as vague as "reorganization reasons". Nor they will be able to say "i fired her because she asked me so". If you quit, you might be penalized by the RAV (you still be entitled to it, only you probably will have to wait sometime before starting to collect).
Again, regardless of whatever you decide to do, time will wash away all this. I totally understand how are you feeling, and though you might believe that thing will not get better, I can tell you they will. Just take one thing at the time and focus to solve things one by one than trying to handle it all the same time.
Best of luck and best wishes!