Hey Brother,
Sorry you're going through this at such a young age. Unfortunately, no one can answer this question with any degree of certainty. Trust me, we have all researched the hell out of this. I have seen some posters have hair line regrowth with finasteride, but they are few and far between. I believe studies have shown that there has been maintenance at the ten year mark. Some people have reported much longer. If it works for you, that is awesome news. I would also consider minoxidil. Good luck and feel free to post pics if you want even more advice from people on this forum.