Magento – Site stuck on “Error Processing Request: SQLSTATE[HY000] [2002] No such file or directory”

I was making some changes in a phtml file to my Magento store

There has been an error processing your request
Exception printing is disabled by default for security reasons.
Error log record number: 927546133845

I now cannot get any access onto the site or into my admin system. Looking at the report for the number above I have but being new to magento i don't understand any of it:

a:5:{i:0;s:48:"SQLSTATE[HY000] [2002] No such file or directory";i:1;s:1575:"#0 /home/xxxxxx/public_html/lib/Zend/Db/Adapter/Pdo/Mysql.php(96): Zend_Db_Adapter_Pdo_Abstract->_connect()
#1 /home/xxxxxx/public_html/lib/Varien/Db/Adapter/Pdo/Mysql.php(320): Zend_Db_Adapter_Pdo_Mysql->_connect()
#2 /home/xxxxxx/public_html/lib/Zend/Db/Adapter/Abstract.php(459): Varien_Db_Adapter_Pdo_Mysql->_connect()
#3 /home/xxxxxx/public_html/lib/Zend/Db/Adapter/Pdo/Abstract.php(238): Zend_Db_Adapter_Abstract->query('SET NAMES utf8', Array)
#4 /home/xxxxxx/public_html/lib/Varien/Db/Adapter/Pdo/Mysql.php(428): Zend_Db_Adapter_Pdo_Abstract->query('SET NAMES utf8', Array)
#5 /home/xxxxxx/public_html/app/code/core/Mage/Core/Model/Resource.php(169): Varien_Db_Adapter_Pdo_Mysql->query('SET NAMES utf8')
#6 /home/xxxxxx/public_html/app/code/core/Mage/Core/Model/Resource.php(110): Mage_Core_Model_Resource->_newConnection('pdo_mysql', Object(Mage_Core_Model_Config_Element))
#7 /home/xxxxxx/public_html/app/code/core/Mage/Core/Model/Resource/Setup.php(141): Mage_Core_Model_Resource->getConnection('core_setup')
#8 /home/xxxxxx/public_html/app/code/core/Mage/Core/Model/Resource/Setup.php(234): Mage_Core_Model_Resource_Setup->__construct('core_setup')
#9 /home/xxxxxx/public_html/app/code/core/Mage/Core/Model/App.php(417): Mage_Core_Model_Resource_Setup::applyAllUpdates()
#10 /home/xxxxxx/public_html/app/code/core/Mage/Core/Model/App.php(343): Mage_Core_Model_App->_initModules()
#11 /home/xxxxxx/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#12 /home/xxxxxx/public_html/index.php(87): Mage::run('', 'store')
#13 {main}";s:3:"url";s:13:"/browse/cases";s:11:"script_name";s:10:"/index.php";s:4:"skin";s:7:"default";}

Can anyone help? I urgently need to get this site back up