The heart is there to be broken....
Mawlana Mufti Muhammad Shafi (RA) is said to have cited an example with regards to the heart being there to be broken.
In the old days there used to be hakims (traditional medical practitioners) who used to grind herbs and prepare medicines of different sorts. In order to do this they would have to burn gold and other metals. They produced tonics that would provide great energy. Mawlana Mufti Muhammad Shafi (RA) used to say that if you grind your desires to pieces, to powder and burn them to ashes they too will turn into tonic. You will gain strength to establish a relationship with Allah (swt) and get love for him. Your heart will become the centre of light from Allah (swt). The more you break your heart the more it will become beloved in Allah's sight.
The more you strike it, the more it will be dear to the maker. He has made it so it may be broken, that its desires be trampled upon for his sake. And when it is crushed it turns into something else.
Mufti Taqi Usmani then goes onto quote a verse of a poem recited by Dr. Abdul Hayyi (RA):
We will turn it into something else. We will convert it into what we like. So, do not suppose that you are being hit by crushing the desires of the soul. Rather, the sweet taste that it will have after the heart becomes the home of Allah's love will disclose that the taste of sins that you used to have was nothing in comparison.
Mawlana Rumi (RA) says about base desires:
The wordly desires are like fuel. Do not regard the desires in your heart as weak. They are useful. The more you burn them, the more taqwa will brighten your heart. You get the desires to do this or that-do not say that they are useless. Allah (swt) has creted them with wisdom. It is that you burn them, as you do that they grow taqwa in you. Endure hardship, but burn the desires.
The more your heart breaks the more dear it is to its Maker. Once you do it, ALLAH (swt) will grant you a sweeteness that will exceed the sweeteness of sin.
Source: Mujahidah an Nafs