Based on his breaking into your emails and impersonating you online, you would probably be able to obtain a protective order that would prevent him from contacting you. Well, technically it wouldn't PREVENT it, but he could be arrested for doing so.
Just one thing to consider along with the great suggestions above. An order might keep him out of your life to the maximum extent possible and give you enough peace to pursue the suggestions above. If you would like to look into that, contact your local women's shelter or call the DV hotline and speak with an advocate.