If Magento redirects to your old domain, and you just changed the domain, you need to make a small modification to the Magento database.
Find the table core_config_data and insert your new domain to rows where path is web/unsecure/base_url and web/secure/base_url
You can also update your Magento database with these two queries:
UPDATE core_config_data SET value="http://www.newdomain.com/" WHERE path="web/unsecure/base_url"
UPDATE core_config_data SET value="https://www.newdomain.com/" WHERE path="web/secure/base_url"
Remember the trailing slash (‘/’) or content is not loaded properly.
That will fix the problem.
This is tested on Magento 18.104.22.168 but will likely work on all newer versions.