mysql and php with so slow after attack

[atokatli]

hi,
an attack occured last week
and after that attack
mysql and php are started to give very very slow rates
according to the one week ago
attack is made to web page
and when I look to the mysql error file from mysql administrator program, it is showing so many error files, approximately 350 pages
how can I delete the error files
and how can I make the system one week ago

are you thinking that the slow rates are occuring from the error files great size

one week ago a page is opened in 6seconds
but now a page is opening in 15seconds

the slow rates is occuring only in php pages
subdomains did not influce

please help me