Error Establishing a Database Connection

At first I wasn’t able to access my dashboard or even see my blog online. I kept getting a parse error message. I think reuploaded my earlier version of wordpress 2.7 (or replaced the corrupted files with the original ones). After doing so, I got an “Error Establishing Database Connection” message whenever I try to visit https://www.tinymaestromusicblog.com. Can anyone help? Thanks!