My Wife [F 20s] is Upset That I [M 20s] Am Never In the Mood for Sex, But She Won't Put Herself Together

TL;DR at bottom.
Right off the bat, I want to make it clear that when I say my wife no longer "puts herself together" I'm not saying that she stopped wearing clubbing dresses all the time or doesn't wear as much makeup as she used to. We live together. I think it would be unfair for me to expect her to have to stand in front of the mirror for an hour just to lounge around in her own home. If she wants to let loose in her own house every now and then, who am I to judge?
Rather, when I say she no longer puts herself together, I mean she'll go days (sometimes weeks) without showering or getting out of her pyjamas/comfort clothing. She works from home and has literally no one in her life other than me. I am her only family, her only friend and her only social contact. When we do groceries, she'll go shower and brush her teeth or whatever. But because she won't step foot out of the house for a week at a time (other than to sit in the car to go to a drive thru), she feels no need to keep up her appearance.
I feel bad saying this, but she also has a smell. And again, I don't expect her to smell of perfume 247. But when I walk by her and can only smell BO, there's a problem. And when we do have sex (maybe once a month) if I use my hands at all, I need to keep them far away from myself or I'll gag. I'll also make a point of not breathing through my nose the entire time. I know vaginas have their own smell and that's fine. I doubt my balls smell like flowers and sunshine. But I've never in my life had to exclusively breath through my mouth during sex to prevent myself from gagging.
I know that there are some mental health issues at play here and am not looking for answers pertaining to this. Not because I don't care, but because that's another issue that we're already working on. I just don't know what to do about this particular issue.
My wife gets upset that we don't have sex like we used to. She, at one point in the past, even used the term "emotional abuse" to describe my innability to put out. But I think that's unfair. I don't believe you can slam someone for having less sex with you if you go from makeup, hair extentions and sexy clothing to pyjamas and extreme body odor overnight.
I don't know what to tell her. My current strategy of making up excuses (I've been having an outrageous amount of "stomach pain" for the last couple years, some real, some made up) ends with her getting upset that we don't have sex, even if she no longer actively gives me **** for it like she used to. But if I told her that I'm not attracted to her because of her extreme BO and innability to put herself together, my life would be hell. I already spend at least 30hrs a week being her emotional punching bag on account of said mental health issues. If I told her what's really going on, I'd lose my mind. I don't know what to do. I can't spend the next two months hearing her yell and cry and everything in between for ten hours a day (I'm not exaggerating). I just can't. I've already made posts here under a sifferent account regarding her tendency to use me as an outlet for her depression. I can't knowingly make that situation worse.
TL;DR - Wife no longer takes care of herself. To give an example of the severity, her BO is sometimes so extreme I can smell her the second I walk in the living room. She has mental health issues which result in her venting at me for 30hrs a week minimum. She gets upset that we no longer have sex. If I told her why we don't, I'd spend the next couple months being her emotional punching bag for much longer than the current 30hrs a week and I just can't do it. I don't know what to do, but I can't tell the woman who uses me as a human vent that she is imperfect in any way. I just can't deal with the fallout that would create. What the hell do I do?


Source.