Moving Domain.wordpress.com to a new domain

If I am correctly understanding your setup, you are using wordpress hosting now, but want to make your domain be a self-hosted copy of your blog

1) Export all your current blog entries/layouts/etc.
2) Change new domain not to forward to the existing blog.
3) Set up wordpress on your new domain
4) Import all your blog entries/layouts/etc.
5) optionally, delete wordpress hosting once all is done.

Here’s a blog post that will give you some examples of plugins that will backup/restore your blog, which is what you need to do to export/import:
http://www.carefulcash.com/the-3-best-backup-solutions-for-a-wordpress-blog/
Though, certainly you could do your own research and find others that you prefer.