Looks like something went wrong with your JETPACK plugin. You’ll need to get into you your server and access your FTP files. Try this:
– get into your server and get into the FTP files then try:
Locate the folder wp-content/plugins and rename the Plugin folder plugins_old. This will deactivate all of your Plugins
There is an article from the CODEX about dealing with this stuff
Let me know if that worked out ??