Fatal Errors and cannot login

After creating a new post, it would not publish and gave me Fatal Error codes. Then, I could not login to change/help the situation.
Trying to get to the Dashboard gives me this code-
Fatal error: Allowed memory size of 41943040 bytes exhausted (tried to allocate 30720 bytes) in /data/15/2/70/121/2559936/user/2806124/htdocs/blog/wp-content/plugins/jetpack/modules/sharedaddy/sharing-sources.php on line 384