|No, you can't use your own IP.|
The only way to ensure you have the same IP all the time is to contact your ISP, find out if they offer a "static IP address" package (likey a business class package). If they do, you can order it from them. It will cost more per month than the normal DHCP setup.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.