fatal error

Hello,

I hope someone can help me. After trying to install a plugin this error message appeared.
Fatal error: Cannot redeclare mycustomStyles() (previously declared in /home/deb45294n2/domains/safehavenonlinetherapy.com/public_html/wp-content/plugins/font/Font.php:170) in /home/deb45294n2/domains/safehavenonlinetherapy.com/public_html/wp-content/plugins/fontsforwebcom-webfonts-plugin/WPFontsForWebwebfontsplugin.php on line 126

Now I cannot use the site at all every page goes back to this message. Anybody know how to get rid of it?

Thanks in advance,

Mieke