Almost everyone feels the same in this aspect.
The fear that rushes through you when you're wanting to approach a stranger can be overwhelming and overstimulating. Some of the most common fears in the world, are public speaking and confrontation.
In my experiences in the past 5 years as a photographer, I have been sifting through the fears and worries that once held me down. I mean we're all human, and going through events in life and learning about yourself and what's best for you is a tough, but - totally worth it journey.
Learning how to approach a stranger on the street is never an easy thing to do, however it has been the most utmost and amazing skill you can experience. Being able to connect with them, even just for a brief second, when moments before you were probably never going to see each other again, it makes me feel like I made a sort of impact on their life. A sense of motivation for me to do this, and it should be for you too, is what this can do for you as a person, and also as a photographer/creative. Just this past weekend at Michigan State Football's Homecoming Parade, I met this amazing couple with their Great Dane and I asked if I could get their photo. They were caught by surprise, but were more than happy to get a picture. I even had a nice little conversation with them about how their day was going.
Simply giving a stranger a compliment, and letting them know that someone in the world appreciates them, can make their day, or even save their life. Having such power, and using it for the good in the world makes me feel like I can change the outlook on the world for each person I interact with.
What most helped me with not being scared to approach strangers, is realizing that they feel just as you do. Everyone is naturally going to only be comfortable talking and interacting with who they're familiar with. Once you find out and fully acquire the mindset that "no one cares, and your false sense of them judging you is wrong", this will make you so much more eased into interactions between anyone on the street, subway, workplace, or even in a classroom.
Go out today, in your normal daily routine and compliment a stranger. Ask yourself how does this make you feel? How do you think it made them feel? How would it make you feel if that stranger had complimented how amazing your new haircut is? The amount of LOVE that could be spread around, the amount of networking connections you could make for an amazing career change or opportunity to change your life around.
YOU are the only person that's able to make the world, and your life a better place. Go out and just try, there will be many people that are uncomfortable, and many NO's. However, the better you get with communication the easier it will be to approach a stranger.