Ankle pain that is worse at rest. what can i do?

See : A doctor for evaluation. It's very difficult for us to answer without specifics because there are to many possibilities.

Mind focus on pain: When you are quiet and trying to fall asleep, you become more aware of pain and that is one reason why you perceive more pain at rest. Also, with some forms of arthritis motion helps pump the fluids out of the area so there is less pressure on nerves when active. At rest, when the body is repairing the damage from activitity, inflammation or extra fluid enters the joint thus causing pressure.