Yes, I think you are way overspined. The left inpact also confirms that. I think Chad is right in there with 2016. However, you may need to go even weaker.

The closest to you that I'm shooting is a 70", 60#'s at 29" Schulz longbow. I shoot 2016's with that. I also have a Hill Croc that is 58#'s at 29" that I also shoot 2016's with, but they are a tad bit stiff.