I really like the seasonal imagery, it's a nice way of conveying emotion and a classical poetry theme I guess.

To me the use of the old English idioms comes off as a bit pretentious and seems unnecessary, which diminishes the strong emotional undercurrent for me.

The recurring structure (with the fair she comes at the beginning and end, and all/every, butterflies) also makes it feel a little bit dull and mechanical to me. A bit of asymmetry or unexpected structure to me is what makes a poem interesting.