I think your mom needs to see her doctor and get evaluated as to why she is behaving like this. It could be many things, like Dementia, but you truly need a professional to diagnose her at this point. I'm sure she isn't doing these things on purpose, so try not to take it personally. But do get her in to see somebody. Take care..
Forgetting things can be the onset of may conditions. It would be wise to have her evulated and see what the experts think. It would easy for any of us to suggest a condition. But we would all be guessing. Alzheimers at its earliest form brings on forgetfulness and the likes. But I wouldn't even suggest she had that. It would be wrong of me to do so and cause you worry. But understanding she has problems is a good thing. That way you might go a bit easier on her and not take things she does or says in a personal way. She probably forgets she says half the things she says within an hour and may act like nothing at all has even happened. But we won't know until she is checked out. Obvious answer I know. But we are not doctors and the problems don't sound much like anxiety.
You didn't mention your Mom's age, or any past medical history, or past mental health issues. Like Mr.Green said, we could guess all day a few different things that could be going on with your Mom, but we would only be guessing. The best bet is to get her to her doctor so he/she can start looking into causes.
One thing I will mention is if your Mom is elderly, UTI's (urinary tract infections) often cause confusiion, and abnormal behavior before it is treated. However, your Mom's doctor would rule out those kinds of things when doing a work up.
Best of luck...let us know how she's doing!