"I felt a Funeral, in my Brain" sounds like a child trying to tell a really depressing story. This kid has spent way too much time hanging around funeral parlors.
Children tend to tell stories that focus on them exclusively, and the speaker of this poem keeps the focus firmly on herself. "I felt […] I thought […] I heard." She tells the story in sequential order, without any fancy narrative tricks. The story comes out in short clips, like a kid who tries to remember exactly what happened.
Although the lines are relatively short, there are lots of pauses. Many of the details are either out of place or kind of unnecessary. For example, it doesn't help us any in imaging the place she was "wrecked" when she points out it was "here" (16). And the last word of the poem, "then" (20) – when exactly is that? Like a child still learning how to build a story up to some kind of punch line, the speaker seems to trail off at the end. If she had just stopped with the fall, it would be a perfect punch line.
The syntax of the poem – the way words are strung together – mimics a child-like voice. Just look how many lines begin with the word "And." OK, we'll tell you: ten. Ten lines in a twenty-line poem! We don't know about you, but we hear our little cousin describing the birthday party he just came back from: "And there was a clown, and he made us all balloon animals, and then they cut the cake, and I got the biggest piece!" Using the word "and" is probably the simplest way to put a narrative together: that's why kids use it so much. So does Dickinson, and not just in this poem. Read some of her other works and you'll see that "and" is one of her favorite words.
Obviously we don't mean to suggest that the poem is as simple as a story that a child would tell, or that Dickinson tells it in this way because she's not capable of anything else. In the world of Dickinson's poetry, everyone is child-like in the face of the awesome forces of the universe, which we can't even begin to fathom. She once wrote that, "Had we the first intimation of the definition of life, the calmest of us would be Lunatics" (source). The stilted, song-like rhythm and syntax are an essential part of the poem's meaning.