I think Tracy is absolutely right - getting over your aversion to interacting with people you don't know and asking questions in class all comes down to practicing. Have the discipline to push yourself outside of your comfort zone each day. Tracy's suggestions for speaking in class are applicable to social situations too. Challenge yourself to start a conversation with a stranger each day. It doesn't have to be anything ground breaking - make small talk with the person next to you in line for coffee or checking out a book in the library. Smile at a stranger you pass walking to class. Strive to make small, incremental changes each day, and I think you will surprise yourself at how much easier interacting with people you don't know gets.
You will get out of your college experience what you put into it. Staying in your room all of the time is not a recipe for success. Many of your peers feel the same way you do right now. A great way to meet new people is to find and join organizations you are interested in. Get involved, meet new people, make mistakes! You will feel uncomfortable at first and the first months may be very difficult but I promise you that the juice will be worth the squeeze in the end.
I hope this helps - don't hesitate to reach out. Good luck!