Cortisol helps us deal with stress by shutting down unnecessary functions, like reproduction and the immune system, in order to allow the body to direct all energies toward dealing with the stress at hand.there will be no separate mellow place that brings peace.it is in the mind when we decide to be positive and take the problems as challanges that prove us, half of the mental peace will be at your side.being physically fit helps us to deal with problems effectively and also we can work more effectively.so to maintain fitness one has to take balanced diet,avoid junk,avoid negative thoughts,avoid people who constantly discourage us and regular yoga with pranayama will help in bringing mental peace. regarding your sick daughter hiring a domestic help temporarily,discussing her problem with a qualified dr so that what measures are required to cure or control her illness will help you in managing stress yourself without your husband on board.