Hi Jessica Jane and warm welcome to the forums
You've taken a great step in coming here and sharing your story. Living with someone who has a mental illness is very demanding and having an unhygienic environment is not physically or mentally healthy as you say.
Do you have someone you can talk to? Another family member for instance - grandparent, uncle, aunt?
Being abused is not good and my heart goes out to you. I do understand it is tough as I too have lived through it. Both my parents had undiagnosed mental illness. It was tough and as you say it isn't a good environment to raise your child.
I don't know the circumstances for your mother or yourself. But I agree that removing yourself from that environment is a healthy move and you oughtn't feel guilty about it. What I would do though is ensure there is a support network set up for my mum. Make sure there was a service that there was a Mental Health Service, Community Health service and a weekly/fortnightly cleaning service (provided by an organisation). These services should all be available free of charge for people on low income or health care cards.
In addition you could make a commitment to yourself to visit her on a regular basis - just to make sure everything is okay.
Now having said all that, I don't have all your circumstances so not sure if any of this is feasible.
To help yourself, maybe visit your doctor and discuss how you are feeling. It might be worth getting a referral to a health professional, e.g. psychologist, counsellor?
Hope some of this helps Jessica Jane.
Keep reaching out if and when you want to. Feel free to browse and to join conversations here on the forums that relate to you.