I would tell you forever but I see others here have mentioned that.
If you are really bent on leaving at one point then you need to establish with yourself a few things. 1) a Rebbe that you are close with that you can ask him anything. 2) the skills to able to learn by yourself and the knowledge how to navigate through learning. 3) enough emunah and yireh shamayim/spritual drive to last your life to get you past all the tumah out the there. Good Luck. Probably easier for stay in learning 🙂