Unable to Delete Page or rearrange nav-menu

Hello,
Am trying to delete a page or remove a category by rearranging in nav menu. But the problem is its taking too much of time and ultimately a blank page shows and its neither getting deleted nor getting saved. Similarly when i am posting a new post when i publish it it takes a long time and ultimately shows a white page. Everything was fine and it started happening suddenly. i did not install any plugin in between normal functioning and when the problem was noticed.
Its a hosted godaddy managed wordpress account so i dont have much idea on coding etc.. Please guide me..
website : pixelpluck.com
thanks