Consequences of sinning
Sinning causes the heart to blacken, it causes depression and anxiety and it causes to deviate from the straight path at which Allah has bestowed his favours. Those who continue sinning without seeking help from Allah and without seeking forgiveness from Allah and without turning towards Allah are readily going to go through depression and anxiety. Happiness and contentment comes from staying on the right straight path on which Allah has bestowed his favours. If we keep on sinning we are likely to deviate from the straight path as directed to us by Allah. Being a sinful person our happiness and contentment are compromised. Having committed sins saddens our heart and soul. In the end what i would like to say is that we should constantly ask Allah to forgive us as every son of Adam is vulnerable to sinning.