Could you start by posting some technical info? Here's some ideas to get you started:
• make and model of cable modem • make and model of router • cox speed tier • signal levels from »192.168.100.1 or whatever your modem config access IP is • speed test results • are you connected wired or wireless? • have you tested speeds bypassing router if you have one? • are other services such as phone or tv affected?
Welcome to the Cox Forums! We're happy to take a closer look at what might be affecting your internet speed. If you can provide some of the technical info suggested by Chris_c21, it will be easier for us to assist you.