This does sound very negative and hurtful. Yes, it is good to be alert and aware in a large city. But you are an adult now. How hard it is to live with someone who yells. You are in my thoughts. What about joining a club of some sort? What are your interests? Can you find a group with similar interests? A craft? Books? Writing group etc? Then you may meet someone else with a car.
Do you have any plans to move away? Can you leave your family? Sorry - I know that is a huge question. But it is hard to stay sane while living amidst such anxiety. I'm sure your mother is dominated by her own fears and it is more about her own anxieties than about you... but when it is directed your way I imagine it makes little difference.

Elana