There are two possible problems you could be having: either there is dirt or other gunk that has gotten in or around your rotation button, or there is a problem with the control panel. Take out the button to clean it or replace the control panel to fix the issue.
The fan blades could be damaged. You can replace the blades, or see if there is anything blocking their movement. There could also be a problem with the motor as a whole. Use this guide to check the fan blades and replace the motor.