Cannot access wp-admin after dashboard install

HI,
I installed the dashboard and was on my way to activate couple of plugins I liked. It said there was some error. So I went into the wordpress plugin section and delete some old plugins and manually tried to activate wpmdev plugins. I got a blank page. Now I get bank page, when I go to http://www.wallbreakers.co/wp-admin/

Thanks in advance, I am not a programmer etc.

Cheers

Humphrey