My husband and I began living and caregiving for mom since February 2012. At first is a real strange feeling to be living in her house. At times I resent being called on, because I'll be in the middle of something. She's so insistent that I have no more interest in doing anything for me. Is it normal to feel like you lost your self?
If this is new behavior for her, there could definitely be a medical cause. Her doctor should definitely know about a drastic change in personality.
If this is how she has always been but it is now intensified as you try to live with her as an adult, I think you are going to need to learn some new coping skills! There are several people on here who have successfully dealt with this kind of parent and others who are working through the problems involved and can share their struggles and successes. I hope they'll be along soon.
Me? I have never heard my sweet mother belittle any of her seven children or grandchildren or great-grands in her life. If she started now we would all be certain she'd had a stroke or some other medical event.
Good luck!