It is highly likely that you can ask your hosting provider to install php 5.6 and you can continue using your existing code. Or you can switch hosting providers, because most will let you choose your php version. The only version your code won't work on is PHP version 7.
In order to upgrade your pages you can download and install the DataBridge 2 beta linked on the top of this web site. It has conversion functionality that can do most of the work for you.