No one can visit my mother because her house is a hot mess. I am not even allowed. People are starting to get made at her because they can’t visit, what can I do about this?

Offer to take her OUT. Tell her to be ready and you will take her out for a nice lunch, or dinner.
Perhaps your mother has a 'hourding problem' that needs to be addressed.
My mother meticulously kept everything in her home, but refused to let anyone help her 'clean out' all the stuff she had accumulated. BUT... after asking her if she has any extra 'clothes' for the needy, or .... (insert item name here) she was only too happy to help out. It took quite a while for her to clean out her closets, but we made quite a dent in the collections!