Re: Docter's certificate
Sorry you are having a bad time at work. The reply to your answer is that it depends very much on your doctor.
However, will it solve the problem? The situation won't change even if you have a few days off. When you get back they might start all over again, and possibly worse as you have had time off because of it, so they might see that as a 'weakness', I am sorry to say.
You need to find a permanent solution to this, somehow. Talk to HR perhaps. Or start looking for a new job NOW. Bonne chance.