Tell you, I am a former seminarian who was kicked out (thanks to God!) though I wanted to stay. I am happily married but still now i would prefer to be a priest. But God wanted me to be a family man, happily, I am doing His Will.
It is not because you want, that God wants you to be a Priest. Priesthood is a calling. I think (my opinion (MO), believe me !) that you are too young to make this decision. MO, dont try to cut corners . MO, go to University, take and degree, meet girls and go to parties, and if God wants you to be a priest, you will be a priest. If God does not want, you will never be, no matter how hard you want. MO, the Church nowadays needs priests who are engineers, doctor, phisicists, biologist, literate so that it may dialogue with the complex knowledge world where we are. You need not only Philisophy and Theology.
As for age, I knew of a guy who after becoming widower, entered the priesthood 65 years old.
You are young, that’s not your fault, sang the other guy. Carpe diem, enjoy life and live life at a time. There is a Russian proverb that says: “When Man makes plans, God smiles (laughes?)”