Mother soils herself and feces all over room.

I agree, it's time to place mother now. In the meantime, dress her in an Alzheimer's anti-strip suit available on Amazon. Put the adult brief on underneath the suit, then change her every few hours. She'll be unable to take the brief off and make a mess with her own waste.

Here is a link to one example of an anti strip garment.

https://a.co/d/9HhH3Ul

Go to Amazon and search out "Alzheimer's anti-strip clothing women".

Also get some Medline Extrasorbs disposable chuck pads for the bed and funiture
here:

https://a.co/d/hvjGl27

Best of luck to you.

Listen to the others , this is too much for you and your family to handle at home any longer .

If this is a sudden and drastic change in behavior , take her to the ER to be evaluated for UTI and/or other issues .

The social worker at the hospital can help you with placement .,

She needs to be in a home and it’s now neglect if you don’t put her in one.

the carpet has to be ripped out with the padding and the floor has to be treated as it’s contaminated now. The baseboards have to be ripped out too.

You probably need to call 911 and tell them she is incoherent or has chest pain and get her out of the house immediately.

You’re probably at least at $5,000 worth of damages now.

You are going to get used to the smell but its going to be overwhelming to anyone else so you wont be able to hide it.

After you get her out, you probably need to be honest with the landlord about what happened and come to an agreement about how you are going to repair and replace the damage.

Sadly your mother is past being able to remain at home with what you're describing. It's not healthy for anyone living in that house.
It's now time to be looking into placing her in a memory care facility where she will receive the 24/7 care she requires and you can get back to just being her child and advocate.
And if money is an option you'll have to apply for Medicaid for her.

I think that your mother may need in-facility care now where there is around the clock 24/7 care, monitoring, and mattresses and furniture that can be cleaned. This doesn't sound survivable for you long term really. I am so sorry, but I can't imagine how this can be handled. I hope others have suggestions for you.