Login page not working

My wordpress theme "candidate" is working fine but when i try to log in with my credentials, it refreshes the page and returns me to the same log out state. When i enter a wrong username and password, it recognizes it and states it to be incorrect. All i need is for the site to correctly log me in and being an administrator, I should be able to view the wordpress top nav. If i log in with the url containg [login to view URL] i am able to log in fine but for some reason its the site itself. [login to view URL] is the site. this is an urgent job and i need to have this fixed ready for presentation on Sunday evening. (its a political site so i need it ready for presentation)