Shyness isn't going to get you anywhere in the world. You have to talk with people no matter what you choose to study. Uni is mostly group work so regardless if you do engineering or not you will be talking to lots of people. Once in the workplace, employers look for soft skills as well as expertise. If you are a HD student and know everything but can't give a presentation to a group or pitch an idea, you will be at a disadvantage. Go to Uni open days, talk to people and improve your skills. Get out of your comfort zone and be uncomfortable, it's the only way that you're going to improve yourself.