Last week, I was configuring a selfhosted wordpress site (onlineearningguru.com). I also had a the same domain configured at wordpress.com (wordpress.onlineearningguru.com). After making few changes, suddenly the admin login started redirecting to wordpress.onlineearningguru.com. I worked for more than 4 hours to find out what changes in the setting triggered that. I hope my experience in solving that issue could save your time if the same problem arises.
That usually happens if you changed the WordPress Address (URL) of your self hosted WordPress site using General Setting. Once you changed it and saved, now you will be redirected to the WordPress.com admin panel.
The solution for this is to change the WordPress Address (URL) from database itself. For this you are required to have access to you self hosted site’s Cpanel. Please follow these steps:
1. Login to self hosted site’s CPanel.
2. Go to phpMyAdmin
3. Select your database
4. Select a table named PREFIX_option and browse it. (PREFIX depends on what you had used while creating your database during WordPress installation)
5. The first row of this table contains the siteurl information which, for now, is the address of the site that you are getting redirected to. To change it, click edit.
6. Change the siteurl to your self hosted blog address and click OK.
7. Now you should be able to find your admin login page.