Suddenly Connection Timeout Expired

I have an amazon's server and it was working fine till last week. Without any update from me, it is suddenly using 100% CPU usage and when I try to login in the website I'm hosting there, it says the error "The wait operation timed out":

[Win32Exception (0x80004005): The wait operation timed out]

[SqlException (0x80131904): Connection Timeout Expired. The timeout period elapsed during the post-login phase. The connection could have timed out while waiting for server to complete the login process and respond; Or it could have timed out while attempting to create multiple active connections. The duration spent while attempting to connect to this server was - [Pre-Login] initialization=191; handshake=1343; [Login] initialization=0; authentication=0; [Post-Login] complete=12999; ]

The process that takes 100% is svchost.exe.

Last week, when I tried to fix this, I made the pending Windows updates in the server, and reseted the server and it worked alone after a day or two. But now it is back again.

Any idea what's going on?