My husbands is making my life a living hell!

Hi sis dolly,my husbands mistress is harassing via email and phone calls,she is making my life a living hell.Me and my husband has been separated for a few months,we are back togther and busy with counselling,she is phoning us and treating us,she sent me old emails of their conversation and sworing me over email.She go around and telling people funny story about me. Sis,what can i do and what legal action can i take,i have been ignoring her,but it seem its just making thing worst.