How do I access all of my posts?

Assuming you mean here on the discussion boards, you should automatically be subscribed to threads you post in, so you can see all your messages by clicking the 'My Subscriptions' link at the top of the page:

As Camelot points out, this is as close asyou can come using Apple...

https://discussions.apple.com/profile/Angel%20Llorente/subscriptions

Try a Google search.

site:discussions.apple.com Angel Llorente