The spatial distribution is examined of the azimuthal plasma current in highly collisional helicon plasma excited by m=0 antenna. The sheath of intense plasma current is shown to arise underneath the antenna due to the generation of strongly damped electrostatic Trivelpiece-Gould waves via mode conversion of the helicon waves. The radial width of the sheath is substantially smaller than the collisional skin size and drops inversely proportionally to the external magnetic field. The dependence of the plasma load resistance on density saturates when the plasma countercurrent becomes strong enough to cancel the antenna fields in the plasma interior. Computed resistance is shown to agree well with measured values under various conditions.