The connection was reset (no replies)

Hello!
Since last update all I can do is to log into piwik...I get 'The connection was reset' for every click after that - when I try to check stats for my other site or try to enter the settings... Also all my sites go down after that for couple minutes. I'm using wordpress. I deleted all files via ftp and uploaded piwik again, nothing changed.
Hope for some help.
Sorry for my English and thanks!