I have a hard time focusing on school work how do I set my mind on wanting to do that rather than play xbox?

To truly. Answer that question, you really need to talk it over with a psychiatrist in your area. All of us tend to focus better on things we like! But for now, disconnect the xbox and put it away. This will limit your playing time as you will have to get it out and reconnect each time. And set a goal of playing no more than 1 hour per day. Ask those around you for help to create external structure.
Game addiction. This is a type of addiction, good thing is you are worried about your studies, so sell your x box, replace it with reading/physical activities, and slowly increase your study hours, cold turkey may be the way to go, you will be surmised there a lot of things you are missing out.