I want to use my own SSL certificate not the shared one, my website is having the shared IP.

You need to have a dedicated IP to be able to use its own SSL certificate rather than a shared certificate.
It means that you will be switched from the Named based virtual hosting to the IP-based virtual hosting, also called dedicated IP hosting, in which each virtual host has a different IP address. The web server is configured with multiple physical network interfaces, or virtual network interfaces on the same physical interface. The web server software uses the IP address the client connects to in order to determine which web site to show the user.