I really wish that I looked intimidating, or was unable to get physically hurt, or have the sitting-in-a-car-self-defense-skills in order to let me pick up people who are just walking in this freezing cold here and offer them rides to wherever it is they need to be. Sometimes they are carrying groceries. I just wish I could help them, and I don't mean to think that every person walking means they'd hurt me, but I gotta be safe (and I read the news too much).
Bleh. I dislike when I want to help but can't, really...
One of the good things my ex taught me was how to punch without hurting myself. Now, I still hit like a girl, but I'm not afraid to hit someone if I need to. Most of the issues women have with defending themselves is they've been taught to "be ladies" and to "not get in trouble". If you're in a position where you need to fight, fight dirty.
My ex did MMA, so he knew a bunch of stuff like body weak spots, etc. I had to get over when we sparred, I was going to cause him pain. He held back with me because, well, he was a lot taller and stronger than I was, but I didn't hold back with him. It was kinda cool the first time I hit him and he recoiled in pain, and my hand and arm didn't hurt at all.
All of that to say, take a self defence class. You'll be a lot more confident in many ways, stronger too.