How big is Morgoth

Morgoth's height has always puzzled me. He's supposed to be gigantic - like a "tower" the book says. But on the other hand, he puts his foot on Fingolfin's neck during their duel. Therefore, unless Fingolfen is built like a giraffe, that must mean Morgoth is vaguely man-sized.

A 50-foot tall humanoid's foot would cover the neck, head, and part of the chest. The taller is the harder it gets to try neck stomping. Try to step on a Barbie dolls neck and you'll see what I mean.

Another thing too is that Morgoth squashes Fingolfin with his shield. If Morgoth is truly gigantic he couldn't squash Fingolfin without kneeling or awkwardly bending at the waist. I find it very difficult to picture Morgoth doing flexibility exercises during the duel.

Based on these facts, I'm beginning to wonder if Morgoth is "only" about 9-12 feet tall, and possibly even smaller.

Can anybody help?