Here are some basic tips for dealing with grief:
You will be hit by waves of emotion. Let the emotion happen, and if necessary name the feeling in order to be 'present' for it. Avoid constructing a mental narrative about the feeling, which produces an entirely fabricated layer of secondary feelings, as a way of avoiding the actual feelings themselves.
For instance, one is sad because someone died, so one starts to construct angry narratives about the situation, in order to feel anger rather than sadness.
When emotion becomes too much, allow it to overwhelm you. If you suppress it, it will cause far more damage in the long run. But resume normal activities once the feeling has passed. Do not indulge yourself excessively and put everyday life completely on hold, or you will be acting against your own interests.
Have a plan for the day but do not beat yourself up for days when you accomplish only 20% of the plan because of overwhelming emotion (or exhaustion, as emotion is tiring).
Concentrate on the three things that can be changed: attitude, thinking patterns, and behaviour patterns. Isolate the ideal for each, and be willing to work towards it with God's help.
With everything else, i.e. everything external, keep it simple: change what you can and (ought) and accept what you cannot (and ought not). Very little externally can be changed, and only then with its complicity or if one is acting in accordance with its nature.
At such times, keep things very simple.