I am 46 and I am back in college. I started college 20 years ago with a fine art major- dropped out. When I started taking classes 10 years ago I had no idea what I wanted, I changed my mind about 10 times I finally decided on social work.
You are so young, I know that in the dorm you do not feel young but age is so relative. I feel ancient on campus but in my everyday non school life I feel normal and so will you.
Hang in there~