What can I do to make my writing less choppy?

Recently and in the past I have been practicing writing as a hobby. I enjoy the creative pleasure it provides, but am hitting major road blocks in the process. My trouble is in seeing the big picture. In college I studied math and physics, and am very good at analyzing, but have enormous difficulties when it comes to creating something. Whenever I write, the material always comes out as a sequence or list. I usually end up listing attributes of a character, events, or details of the setting. I can't seem to tie these things together and make a real story. I feel like every sentence I write is disconnected from the rest. What exercises can I do to improve in this aspect?