I have some ideas, but first I'll make the disclaimer that I'm not responsible for what happens if you follow my advice. So think this through before trying any of it.
Idea 1. Get a friend. Someone who has more sense of adventure than you, but is sensitive to your needs. Someone who will encourage you to spread your wings. Someone who can tolerate your mother's meddling, and won't ridicule you for it. Hang out with this person and do stuff that on the surface seems like a huge risk, but is really not dangerous. Maybe play poker for cash, but keep the bets small. Or do something more physical that might cause scratches and bruises, but won't seriously hurt you. With the help of this person, develop some confidence. Then go away with this friend for a few days, maybe a week (camping, music festival, hiking, biking, something). Write your mom a note that you will be back on a certain day, but not specifying where you're going. Then make sure you're back by the time the note said. Or leave without saying anything, just to be out of the house for a while, then return hours later. If this happens enough she might get used to it, or she might freak out each time. If she freaks out, you can't really be at fault, because all you did was go out. Oh, make sure you don't drink, use drugs, have unprotected sex, do anything illegal, or anything likely to hurt yourself. Do safe things. The safer, more boring, and more mundane, the better. Don't give her anything legitimate to worry about. If this gets to her - it wouldn't get to a normal person - and she freaks out, it will become more apparent to her and everyone who sees her that she needs help. This plan has another benefit, which is helping you become independent, confidant, and assertive. Maybe your friend could even help you get a job so you're independent financially.
Idea 2. Turn the tables. Worry about everything she does. Worry that there is too much cholesterol in the food she buys, and at her age, you're concerned about what it could do to her heart. Worry that she is getting too old to drive a car. Worry that any time she leaves, something bad might happen to her. Nag her to sign up for self-defense classes, because there are a lot of bad people out there. The goal is to be so annoying that she backs off. Or better yet, gets a dose of her own medicine, and becomes aware that she is too overprotective.
Idea 3. Replace yourself. Find someone else for her to rescue. I have no idea how you would go about setting this up.
This is just a brainstorm. I don't know how any of these ideas would turn out in reality. I'm not an expert at doing any of these things.