Are you still living at home with your parents? If you are, it's hard to believe they will start loosening the apron strings just because you turned 18. I know, as I had overprotective parents too. I didn't leave home until I was 33, and that was to get married. In their efforts to protect you, their fear did you harm. You can't live a life like that. We just take reasonable precautions, and then go on our way. You can't grow and learn if you remain housebound. I would try walking a short distance from the house to begin, and then when you're comfortable add a little more to your walk. Possibly a friend or relative could accompany you. Walking outdoors is a great way to relieve anxiety, and brighten up your mood.