It's not easy, some of our most valued and fulfilling experiences are often colored with a tinge of pain. Good days and bad days will be quite normal for you to see-saw up and down between feelings of coping and despair. As time goes on you will experience more peaks and fewer troughs and the troughs will become progressively shallower.
Part of coping with grief is learning to tolerate and work through painful emotions; it's normal to to feel feel frustration and depression – but please believe it is worth it EVERY DAY to take a deep breath, and START AGAIN.
If you’ve cut out activities that used to be an important part of your life, it may be time to try scheduling them back in. Some of these activities may no longer feel pleasurable, if they remind you of your loved one, they require effort, or force you to confront difficult emotions.... you should consider scheduling them in anyway.