I bought a flashlight taser years ago when they would still ship to RI. You can still buy them out of state or have it shipped to someone you know out of state. Even so, a small taser isn't going to do much for you besides buying you some time to escape if you're lucky, and you have to have it on you at the moment.

I'd try taking a self-defense class for women. Same idea as a taser, it only buys you a small amount of time, but you don't have to carry it with you. My yoga teacher is also a taekwondo black belt and I wouldn't mess with her. She's tiny but evil lol. Find someone qualified to teach you a few basic things and you can carry those with you for the rest of your life. Don't think that just because you're petite you are 100% helpless. Your goal isn't to win fights, but make someone think twice about fucking with you and buy a few moments to escape. And don't forget cardio is your bestie in those cases.