Tracking Script Modification needed

I have a Custom script that is used to control all my websites from one location. every time a page loads with the code that links to my custom script it queries with the database. now as I am adding more of my websites it seems the load on my server is going up and it sometimes is unable to connect to the database (due to the large amount of queries) I am in need of someone to modify the script so it works 100% as it does now but reduces the server load as much as possible and speeds up the queries to the database. Possibly by making the script use multiple databases (multiple databases does not HAVE to be the solution. I am looking for the BEST solution to reduce the server load as much as possible) The Aim of the modification is to reduce the server load as much as possible and increase the speed of the database queries as much as possible While at the same time the script is working 100% as it currently is.