14.04 - Getting error to configure php5 mysql packges

I am trying to configure LAMP stack on ubntu14.04 using Digital Ocean Guide. apache2 configured properly but when I am running below command its throwing error.

sudo apt-get install mysql-server php5-mysql

Error

Err http://ppa.launchpad.net/ondrej/php5/ubuntu/ trusty/main php5-common amd64 5.5.37+dfsg-1+deprecated+dontuse+deb.sury.org~trusty+1
404 Not Found

Err http://ppa.launchpad.net/ondrej/php5/ubuntu/ trusty/main php5-mysql amd64 5.5.37+dfsg-1+deprecated+dontuse+deb.sury.org~trusty+1
404 Not Found

E: Failed to fetch http://ppa.launchpad.net/ondrej/php5/ubuntu/pool/main/p/php5/php5-common_5.5.37+dfsg-1+deprecated+dontuse+deb.sury.org~trusty+1_amd64.deb 404 Not Found

E: Failed to fetch http://ppa.launchpad.net/ondrej/php5/ubuntu/pool/main/p/php5/php5-mysql_5.5.37+dfsg-1+deprecated+dontuse+deb.sury.org~trusty+1_amd64.deb 404 Not Found

Also I tried to install php5-common packge using below command

sudo apt-get install php5-common=5.5.9+dfsg-1ubuntu4

But its tried to install package php5-json but that also return 404 error. Please help me to get this done. I want to install php5.6 version not php7. Thank you.

Finally I discovered why I am getting this error. I have an unofficial PPA which is breaking my install procedure. this Answer helped me to get it done.

Apart from that I have installed many php5-* modules using package version. For example I have installed php5-common package using below command

sudo apt-get install php5-common=5.5.9+dfsg-1ubuntu4