Welcome to the forum, Tien!
I am impressed that a young person like you have this Noble goal.
Sadhu! Sadhu!! Sadhu!!!
You seem to be doing the right things. Read the Meditation and Living Dhamma sections too.
Getting to the Anagami stage is not a trivial thing, but of course should be achievable by a determined person with tihetuka birth. Of course, there is no way to figure out whether one has a tihetuka birth or not.
Here is a post that could give you more information:
Craving for Pornography – How to Reduce the Tendency
As discussed there, an Anagami would not have craving for ANY type of sense pleasure: craving for tasty food, smells or body touches (including sex).
However, that cannot be achieved by sheer will power. It comes through comprehension of the fruitlessness of sense pleasures. Jut as with any stage of magga phala, that understanding comes through the comprehension of Tilakkhana at increasingly higher levels.