Lost everything- very confused

Today, I was playing with my blog and I decided to try out Tumblr just to see how it worked. I switched over my domain name allisonrubin.com to see if it worked and it did. But I realized that my posts from wordpress didn’t come over with it.

Now I’m trying to recover my posts but I can’t figure out how to put the domain back on wordpress and I can’t find my posts.

What have I done?