I am a fifteen years old religious teenage boy. A sensitive teenager. And I have a big problem, or rather a big question:

Why is it that although I'm a relatively good person most of my learning is Talmudic studies, I spend most of my free time thinking of girls!
 

Answer:

Do you want to know why this is happening to you? It is happening to you because you are a fifteen year old boy.
That’s the whole story.

It is natural for boys your age to be attracted to girls, especially when you see them all the time.

That attraction is meant to be kept to yourself right now, and at the right time you will use it wisely, maturely and productively

So how do you control your thoughts and urges?

Keep your mind busy with other things. If the money lay around on your desk or in your wallet you would be tempted to spend it right away; that is why you put it in the piggy bank—out of reach and out of sight!

If these feelings are on your mind all the time it is hard to live life normally—so fill your mind with other projects, feelings, thoughts, and activities etc. Have a ready project or thought that you can immediately get busy with every time thoughts of girls come to your mind.

Because they will come to your mind, the question is how prepared will you be.