First make sure that the indent on your auxiliary is not engaged. Do this by pulling the right drive control lever all the way to the left.
Also, even though I don’t think it would cause this problem, make sure the indent is not engaged on the lift arm peddle. Do this by pressing the peddle all the way down with your heal.
If neither of these work, then you need to lift up the cab and check to see if any of the valves are stuck open in the control valve. Also make sure that all of your linkages are where they should be and in good condition, i.e. not loose or broken.