If you wish to heal your heart and rectify yourself, then you must recite the Quran, reflect upon its meaning and let your heart be moved by it.
There’s nothing like the dhikr of Allah to strengthen your heart and purify your soul, all you’ve to do is make sure you are consistently seeking His Help and that’s only possible when you call on Him.
Messenger of Allah ﷺ said:
أَلاَ وَإِنَّ فِي الْجَسَدِ مُضْغَةً إِذَا صَلَحَتْ صَلَحَ الْجَسَدُ كُلُّهُ، وَإِذَا فَسَدَتْ فَسَدَ الْجَسَدُ كُلُّهُ. أَلاَ وَهِيَ الْقَلْبُ
“Beware! There is a piece of flesh in the body if it becomes good (reformed) the whole body becomes good but if it gets spoilt the whole body gets spoilt and that is the heart.”
Sahih Al Bukhari
Start with Dua’, or recitation of the Quran – whichever it is that you’ve been putting off – as that is where the keys to the reformation of your heart are found.
And this is just the first step.
P.S. : SFN stands for Salah صلاح, Falah, فلاح, Najah نجاح.