Is there any hope that Allah will ease for me the agonies of death and the torment of the grave, knowing that I have repented to Allah after many sins? And can whispering (waswasa) reach the point of self-doubt, and does the fear of being the person mentioned in a certain hadith fall under whispering (waswasa)?

Praise be to Allah who has accepted your repentance and guided you. You must have good thoughts about your Lord, for He is worthy of all goodness, and it is hoped that He will alleviate the pains of death, protect from the torment of the grave, and bestow the bliss of the Hereafter. Just adhere to His law, follow the guidance of the Prophet, peace and blessings be upon him, and strive in supplication while having good thoughts about Him. The cure for obsessive whispers (waswasah) is to ignore them and turn away from them. If they persist, consult a trusted psychiatrist, and you may also refer to the consultation section of this website. We need you to specify the hadith you are asking about so that we can provide you with a beneficial answer.