Originally Answered: First poem I wrote, what do you think?
It has sentimental meaning to you so you probably want to leave it as is, but if you choose to revisit, I would ask you reconsider rewriting the final two lines, they just don't flow right for me, needs a paring down of the words (though the image of not having these memories, of what could have been is a universal feeling, and its well) and perhaps reconsider the line breaks as well. But of course, when something is put down at a time of grief, it often is not for the poetry, it is for the self, and I would gather this served its purpose well, and leaving it as is may be right.
oh, and an offering to the grave, to the departed, to your grandfather: Great idea! It will feel good. Trust me.