The absolute magnitude of the gravitational potential energy inside the shell is larger than outside the shell, but it is uniform inside the shell so there's no gravitational force.
Newton calculated this. Pick a point anywhere inside the shell (your location). Chose any line that goes through that point as the axis of a cone, and construct the whole cone, a "double cone" with both nappes. In general the intersection of one nappe with the shell will be smaller than the other, and so will cut off a smaller piece of the shell, but the distance to the vertex point will also be smaller. The gravitational force from the two cut-off pieces of the shell will be equal, because the size of the cut-off piece is proportional to the square of the distance to the vertex, and the strength of the gravitational force varies as the inverse square of the distance. The small piece is nearer to the vertex by an amount that exactly compensates for the smaller size of the cut-off piece of shell, so the gravitational force from the two nappes cancels.
Since the net force is zero for every part of your body, there is no tidal "spaghettification" force like there is inside a black hole.
BTW, this generalizes to the force inside a shell that is bounded by two tri-axial ellipsoids.