Need urgent help

I shifted my website to another hosting service. I am now facing problem in accessing my Piwik data.
I also updated my Username and Database etc in the config.ini.php file assuming that this will work.
But the following error is been displayed: “The PDO extension is required for this adapter but the extension is not loaded”

Also, if I re-install Piwik anew for the same blog, how can I restore my traffic data? Is there any log file that I can replace to the new Piwik installation and restore all my data?
This data is for more than one year - I cannot afford to loose it. Please help!

“The PDO extension is required for this adapter but the extension is not loaded”

Contact your webhost and ask them to install PDO extension for PHP (which is normally installed by default)