Kim, that is not looking good. It looks like you may have rot at least in the back section of the branch. And since it seems to come from the center, it could spread.
Step no. 1: take a needle and prick in the section just above the middle where it looks the blackest. See what color sap comes out, if any. If the sap is white you're fine. If the sap is black or clear, do NOT prick anywhere else since you could spread the rot. Then it will be cutting time.... but let's take it one step at a time....
