Error establishing a database connection

I have looked at this topic for the last couple of hours and it doesnt help me. Since using WP i have found that when i post a new article ie .co.uk/news/new-article and them look at my sitemap a ghost URL is established called .co.uk/new-artcle. Clicking on ghost takes me to my home page. So on advice i went into the general settings options where it gives you two options

WordPress Address URL:http://mysite.co.uk/news
Blog Address URL http://mysite.co.uk/news

First i deleted the Blog address and it wouldnt save so i deleted WP Address.

Then i got error message telling me to add snippet of code and repair which i did but now i cant even login. Help