Why not list down 3 item that you love about your current job, and 3 items which you hated most. Then for those you hated most try put them into group can be change or can't be change. That way your situation is much clearer, and that you will be able to show your prospective employer why you are suitable for the job offered.

Try not emphasize things which can be change e.g. relationship with your current boss, and colleague, as these are human relationship problems which can be solve. Try focus on things which can't be solve, in this way, you don't reveal your weaknesses.