Sometimes you might be in the situation when you accidentally deleted your SharePoint site from IIS. It's not a disaster, because nothing happened to your site, except you lost the access.
The first thing you can logically try is to create new Web Site in IIS, but this won't help. The solution is restoring site via Central Administration
Navigate to Central Administration ->Application Management and extend the site your deleted from IIS. When SharePoint extends the site it verifies if existing site is in IIS, and if not - creates it. After the site will be extended you will have you original site back in IIS