You are 19 and married ?
Well, there is a lot of the world that you have yet to see or explore. If you think you can be contented just being around him for the rest of your life, good for you.
If not, you should work out a way for you to do more things (hobbies, work etc as others as posted) on your own while not compromising your marriage.
As many here have found out, it is more healthy for couples to have some independent life. Unfortunately, relationships/marriages can turn sour and often do.
Just my 0.02 :D