Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother in Islam, thanks for your question, which emanates from a God-fearing heart and shows your commitment to Hajj, one of the five pillars of Islam. The Prophet (peace and blessings be upon him) said, “Islam is built upon five pillars: testifying that there is no true god except Allah and that Muhammad is the Messenger of Allah, performing Prayer, paying the Zakah, making the pilgrimage to the Sacred House (Hajj), and fasting the month of Ramadan.” (Al-Bukhari) Also, we commend your pursuit of Islamic counseling.
Hajj Mabrur (the one accepted by Allah) has many virtues, among which is that it expiates sins. It is reported that the Prophet (peace and blessings be upon him) said, "(The performance of) `Umrah is an expiation for the sins committed between it and the previous one. And the reward of Hajj Mabrur is nothing butParadise." (Al-Bukhari)
Focusing more on your question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
Excerpted with slight modifications from: www.islam.ca
Although we believe that a virtuous Hajj makes a person washed clean of his sins, and we certainly hope and pray that we are included in this category, it is still too presumptuous on our part to think that we definitely fall in this category; after all, who can say for certain whether our Hajj was so virtuous as to make us worthy of this honor?
Then again, how can we be so sure in our heart that it is good for us to die then and there, and not some other time? Who knows what other works have been destined for us by our Creator?
Life is a gift from Allah; therefore, we must cherish every second of it and utilize it for seeking the pleasure of Allah, our Creator Who is All-Wise and All-Knowing. Since Allah alone knows what is best for us, we are to leave such decisions to Him and surrender to His will. The Prophet (peace and blessings be upon him) said, “No one should wish death for any affliction that has befallen him. If he finds his situation unbearable, let him pray: “Allahumma ahyini ma kanati al-hayatu khayran li wa tawaffani ma kanat al-wafatu khayran li (O Allah, grant me life if life is good for me, and grant me death if death is good for me).”
Having said this, however, I must add a further note: There is nothing wrong— and, nay, it is indeed most meritorious —for a believer to pray to Allah to make death visit when he is in the best act or deed of his life. One of the prayers of the salaf as-Salih (righteous predecessors) therefore was, “Allahumma ij`al khayra `amali khawatimahu, wa ij`al khayra yawmi yawma alqaka! (O Allah seal my life (of this world) with the most excellent and the best work of mine, and grant that the best day of my life be the day I look at Your face!)”