266688 Wordpress Database Error

Hello, When viewing my wordpress blog, I receive the following error message: "Error establishing a database connection." 30 minutes before getting this message, I had installed and activated CaffinateContent plugin on my blog which is for pulling in various content from different websites. I had just configured it to pull in videos from youtube. After doing this I checked the blog and everything was working fine. Then 15 minutes later, I received the error message above. IMPORTANT NOTE: I'm not sure if this is related or not but a few days ago, I logged into my cpanel to update my blog to the latest wordpress version using FANTASTICO, and there was a message there that there that wordpress was NOT installed. This was really strange since I used FANTASTICO to install and upgrade my blog several times. The current version installed now is 2.6. I need for someone who is an EXPERT in wordpress and PHP to fix the error on my blog and update it to the latest version of wordress. Please use the PMB to discuss with me what you think the problem is and how you're going to go about solving it. Please don't just say, "I can do it". Please discuss the issue with me. Thanks.