Sometimes we fall in the trap of thinking that no matter what we do we will never be able to have a strong eman, we feel that we have let ourselves down and we just can't recover from the sins we have been committing, sins that have became like our habits and became a part of our lifestyle. This exact thinking is the reason why we go astray and we stop our good deeds instead of recovering.
If we start seeing a sin as small, even if it was actually small, then this small sin will start getting bigger and bigger until one day we will find ourselves drown in the sea of our sins.
Leaving a sin which became a habit is hard, for example if you have been listening to music everyday then stopping is difficult at first, so don't stop all at once but reduce the amount of music you listen to and switch to nasheed's until you are completely ok without music, then instead of nasheed start listening to Quran, this way you haven't only stopped sinning but also you have converted that sin into a good deed that you'll benefit from in your daily life and in the hereafter.
Allah knows that we are vulnerable to mistakes, he created us this way! The joy you get when you leave something only for the sake of Allah is just something incredible, leaving a sin that was once a part of your lifestyle to make your creator happy is something that Allah loves.
We should always find ways to stay close to Allah, as human beings we don't always have a strong eman sometimes we all slip and fall in the shaitan's traps but that doesn't mean we should stop doing all the good deeds we have been doing.
Instead after we slip and sin, we should do something new as a good deed to erase that sin, as our holy prophet Mohammad peace be upon him told us in this hadith:
وصى النبي صلى الله عليه وسلم معاذاً لما بعثه إلى اليمن فقال :" يا معاذ : اتق الله حيث ما كنت , واتبع السيئة الحسنة تمحها , وخالق الناس بخلق حسن " 0
الراوي:أبو ذر الغفاري و معاذ بن جبل و أنس بن مالك المحدث:الألباني المصدر:صحيح الجامع الجزء أو الصفحة:97 حكم المحدث:حسن
The Prophet (peace and blessings of Allaah be upon him) advised Mu’aadh, when he sent him to Yemen, “O Mu’aadh, fear Allaah wherever you are, and follow up a bad deed with a good deed, and it will wipe it out, and treat people in a kind manner.”
Narrated by Abu Zar Al Ghafari, Mu`aad Ibn Jabl And Anas Ibn Malik, in sahih al jamee of Al-Albani, the hadith is classed as Hassan
We all make mistakes, so whenever you do make a mistake don't forget Allah's mercy and immediately ask for his forgiveness and repent because Allah loves those who repent and always follow a bad deed with a good deed.
And always remember this ayah of the Quran where Allah tells us that he loves those who repent: