Sadly the creative industries are notoriously low income. Are you a trained photographer, or is your photography nearing a professional standard? If so, you could work as a photographer - perhaps occassionally photographing works of art for exhibition brochures and catalogues. Set up your own website with an online gallery showcasing all your work for starters.
Art and photography are both very competitive fields, so you'll need to be a canny businessperson to find a reliable way of making substantial profit out of either. Perhaps you could sell your services to other businesses - offering to provide cheap but personalised canvases for their offices, for example (arty close-ups of their products or team members, for example). Set up a partnership or long-term deal with a company that prints images on canvases to get better rates than they'd offer for one-off consumer sales.
Hope this helps.