Dihedral is the angle between the wing and the horizontal plane, viewed from front/back. Position on the fuselage is where the root chord is relative to the fuselage.
So, an aircraft can have dihedral or anhedral, and can be low, mid or high wing, and the two are in principle independent choices (although there tends to be a correllation, it is not fixed and there are exceptions). Certainly the effect of dihedral can be discussed independent of the effect of wing position.
I referred to not mixing the three concepts because the OP talks of dihedral, sweep and "one wing being lower" and so mixes up the concepts its hard to grasp at the intent of the question (at least, hard for me)