Get a job that can support you. Any job. When you are not at that job, practice drawing. Learn how to use Photoshop. Learn how to use different physical media, paint, charcoals, hell, even collage and sculpture, a little bit. Don't give up drawing on paper if you get a tablet. Be prepared to miss out on social occasions because you need to get work done. Don't just draw concept art. Learn anatomy, sketch studies of interesting things, paint landscapes, do abstract experiments with colour and texture. Do it well and do it all the time. Be prepared to give up some of what you like to support what you love. And remember. Concept art is an industry term for promotional or production artwork. 'Concept Artist' is a job description. Avoid trying to learn a 'concept art style' because that phrase is meaningless. You want to become a great artist, because you love creating and visualising, and then you want to make a career out of it. Concept art is only one way of doing that.