What is the ruling on intense fear of punishment after death, despite performing the obligatory duties and abstaining from major sins?

A Muslim should praise and thank Allah for His blessings and for granting success in remembering Him and fulfilling His obligations, and he should not belittle his sins. Belittling sins is among the causes of perdition and distance from Allah. The believer sees his sins as great, whereas the wicked person sees them as trivial. The fear of Allah and the remembrance of death are praiseworthy matters if they motivate good deeds and are accompanied by hope, without leading to despair from Allah's mercy. For the righteousness of a believer depends on the combination of fear and hope.