I am also 'painfully shy.' As I child I couldn't make phone calls at all, and I still get panicky whenever I have to call someone who's not family or not expecting me to call. I couldn't order my own food in restaurants and I actually went thirsty a few times rather than ask the waitress for more water. I would rather search a whole store or library for what I'm looking for than ask for help, and I never accept associates' offers of help. I can't make small talk. I'm always the quietest person in a group. I just kind of tag along with my friends, making a comment here or there in the conversation, and if I'm with strangers, I try to get out of the group as soon as possible or make myself invisible. I hate parties and dances, because I also just follow around the person I know best, and if they leave for the restroom I'm frozen in place until they return.
I've turned down exciting opportunities because I didn't want to experience them with a group of strangers (such as going on a trip or joining a new group by myself). I haven't gotten a job yet because I'm terrified of the application process (talking to managers, the interview, etc.). When I try to do something new (like banking), I get really uptight about embarrassing myself in front of the teller and end up embarrassing myself because I have to make it clear that I'm new and don't know what I'm doing. I still have to bring my mother to places like banks to walk me through the process, or else I do whatever I can online or through the mail.
If I could, I would do all my shopping and appointments online, so that I would never have to interact with a stranger (or drive, which is another thing I hate doing). However, I've gotten much better at this as I've grown older--when I'm shopping at a place I'm comfortable in, I can even make a little small talk with the cashier. I'm still always too nervous to count out the correct change.
Shyness is the bane of my life. In fact, I'd say what I have is closer to social anxiety, although, of course, the disorder being what it is I'd never be brave enough to see a specialist for it. I've made a lot of huge steps, though, and I've learned that I can do things on my own without dying in a puddle of embarrassment.