No you are not. Most vocation directors agree that the only way to really know that you have a vocation to the priesthood is to go to the seminary and try it. It will become more and clearer to you once you are in an environment where everyone is also discerning the priesthood.
There is no obligation to stay in the seminary if you discover that priesthood is not for you. Some people go to the seminary and eventually become priests while others discover different ways of serving the Lord.