Editing and Improving connection limiting PHP script

Hello, I have a video streaming website on a shared hosting, visitors using download manager applications (e.g: IDM) to download my videos, these apps open upto 16 connections per download, which will waste my bandwidth and overload the Apache, so I modified a script that use php & mysql to limit the connection to 2 conn. per IP address, it worked will but the problem is my hosting provider limit the count of process to 25 and the script running many process which will give users HTML 500 error (screen-shot: [login to view URL]).   So, I need a skilled web developer to optimize the original code to work without any problem in this shared hosting, OR writing new better code.   P.S: This is urgent, I need this asap.     Best Regards, Abdulaziz