Tone: "I Felt a Funeral, in my Brain"

This poem confused me a little but I found it very interesting. The tone of the poem was not completely clear to me but I did find an underlying tone: insanity. The author seems like she is on the verge of breaking down. I explored two possible meanings that could also connect to this tone. My first thought was that she was discussing her own funeral. So, the first time I read it, I felt that the tone was full of morbidness and insanity. The title itself made me question the writer's sanity. You can't "feel" a funeral in your brain. That just doesn't work.
Another meaning that my small group discussed was that she was remembering her deceased husband's funeral. This would also relate the tone. If that is a correct reading, then obviously she is caught up in the past and can't get beyond it. She can't move on and she is driving herself crazy by reliving the memories.