Toilet - Fill Valve water level too high and really can't be adjusted
Your toilet tank fill valve may need replacement if it is not adjustable in the way that I will describe. On valves that are adjustable the overall height of the valve / float assembly may need to be adjusted downward to lower the whole top of the unit. This will lower the overall range that the float works within.
If you need a replacement get something like shown here:

Picture Source
These units are available at home centers and hardware stores and are not that expensive. (Probably about the cost of two lattes at the coffee shop).
Note the portion of the base that is dark gray in color and the upper part that is the much lighter color. That lower part adjusts by screwing in or out of the upper part. This sets the position of the valve / float in the tank. The screw assembly is really just allowing a fine tuning of the water level. Generally the height adjustment is made when installing the unit.