Adding or subtracting a character in the middle of creating a lengthy work is nearly as challenging as breaking up with a longtime life-entangled partner.
You already made your work in the best way that you know how. Now you need editorial advice. That's part of the process for any writer, and being an editor in no way exempts you from it.
There are some projects where artistic urges outweigh commercial considerations, and this sounds like one of those.
The way you feel isn't a rational response to a defined situation, and can't be evaluated on that basis. Feelings don't stay contained and orderly. Some of your feelings may not even be about your writing.