How can I stay focused on something for a long period of time?

I tend to do something like reading or designing or learning a language for maybe two weeks or up to a month and then do something completely different for another small period of time. I would like to be able to get things accomplished, specifically finishing a degree program. I’m unsure if I just get bored easily or if I lose interest for a while or what. So any suggestions on how to possibly overcome this obstacle would be great.