I'm not a huge fan of swearing in poetry but I do believe it has its place, I've used swearing in poetry myself. Sometimes feelings, especially grief become so mighty and frustrating that we can't always be soft with our words. Sometimes we are angry and shaken and I liked how you expressed this. The word just kind of catches you off guard and hits you. It was really striking.
I loved how you combined the soft gentle missing of grief with a wave of frustration. I really felt this poem. It's beautiful.