I don't think the 7th house is your shadow, I think the shadow is ruled by either the 6H or the 8H

Like, you think the other is your shadow, but no, that's just what you don't own, what you avoid being. But, when it comes to the other, you understand it very well, you can explain it, you own it enough to interact with it. It's just what you don't identify as

What is your shadow, IMO? Well, your fears, the habits of yours that you aren't aware of, what people use to control you, what makes you more dependent, what you think you control, but what controls you. And, I think that's better represented by the 8H and 6H