GRIEF COMES IN WAVES. If you've ever stood in the surf at a beach you know what I'm talking about. There are times when the water will roll out, and it's beautiful (this represents the better times) and there are times when the waves roll in and pound you, and sometimes overwhelm or over power you. This is just like grief, sometimes you're doing great and the water has rolled back, and next thing you know you're completely overwhelmed. It can be minute to minute, or second to second, or day to day, or even longer. It's completely normal. When you start to get concerned is when you feel like you're waiting for the water to roll back again, and you start to feel as if you are drowning. 

I must not be a good swimmer. I feel like I'm in over my head sometimes just trying to come up for air. 

Grief comes in waves.