You were right about not being on the correct support forums - you can read up about the difference in com vs org here:
http://en.support.wordpress.com/com-vs-org/

Incidentally, When I visit your correct login link, I do see the WordPress login page. (You probably needed the '.php' part at the end of the address.)

When I type in my domainname.com/wp-login it just takes me to a site index page and not to a login page. What do I need to do to get into my own website?

Also if this is not the right website and I should be at wordpress.org instead, I still don't understand the difference or how to login via that...
Blog url: http://tobinjonesphotography.wordpress.com/