Does Hajj Forgive All Sins?
Question

There is a hadith that means if you make hajj properly, it’s as if you’ve returned sinless as a child. Alhamdulillah, I have made hajj and in sha Allah it was proper, but from time to time during my prayer I remember a sin I have made before hajj and I feel tremendous remorse and I ask for forgiveness. Should I be so remorseful or should I be more hopeful that I have been forgiven and not try to remember my sins?
Praise be to Allah.Reward of Hajj mabrur
Abu Hurayrah (may Allah be pleased with him) said: I heard the Prophet (blessings and peace of Allah be upon him) say: “Whoever performs Hajj for the sake of Allah and does not utter any obscene speech or do any evil deed, will go back (free of sin) as his mother bore him.” (Narrated by al-Bukhari, 1449; Muslim, 1350) 
Here we should draw attention to two things: 

That this is the reward for an accepted Hajj. Whoever does Hajj using haram money , or whose Hajj is not sincerely for the sake of Allah , may He be exalted, or who utters any obscene speech or does any evil deeds, his Hajj will not be accepted and he will not go back as on the day his mother bore him. 

Ibn ‘Abd al-Barr (may Allah have mercy on him) said: 
With regard to the accepted Hajj , it was said that it is that in which there is no showing off or seeking reputation, and in which there is no obscene speech or evil deeds, and it is done with halal wealth. 
Al-Tamhid lima fi’l-Muwatta min al-Ma‘ani wa’l-Asanid, 22/39 
Some of the scholars said that the Hajj mabrur is that which is accepted, and the sign of its acceptance is that the person does not go back to disobeying his Lord, may He be exalted, and that he restores rights to those who are entitled to them. 

Hajj does not mean that obligations such as expiation (kaffarah) and debts are waived .

Never despair of Allah’s mercy
The Muslim whom his Lord, may He be exalted, honours by enabling him to perform the rituals of Hajj should be concerned lest his Hajj has not been accepted from him. This does not mean that he should despair of his Lord’s mercy; rather it is so that he will not take it for granted, and so that he will turn to his Lord, may He be exalted, with sincere du’a, asking that it be accepted from him, and so that he will focus on doing righteous deeds that will increase his balance of good deeds on the Day when he meets his Lord, may He be exalted. Allah, may He be glorified and exalted, says, describing the believers (interpretation of the meaning):
“and those who give (their wealth and other possession) whatever they gave, in a state that their hearts are overwhelmed (with the belief) that they are to be those who return to their Nourisher-Sustainer —
It is these who race for the good deeds , and they are foremost in them (e.g. offering the compulsory Salat (prayers) in their (early) stated, fixed times and so on).” [al-Mu’minun 23:60-61]. 
‘Aishah, the wife of the Prophet (blessings and peace of Allah be upon him) said: I asked the Messenger of Allah (blessings and peace of Allah be upon him) about this verse: “and those who give (their wealth and other possession) whatever they gave, in a state that their hearts are overwhelmed” [al-Mu’minun 23:60]. ‘Aishah said: Are they those who drink alcohol and steal? He said: No, O daughter of as-Siddiq; rather they are those who fast, pray and give charity, fearing that it will not be accepted from them. Those are the ones who race for the good deeds. (Narrated by at-Tirmidhi, 3175; Ibn Majah, 4198; classed as sahih by al-Albani in Sahih at-Tirmidhi)
This fear of these believers does not make them despair of the mercy of their Lord; rather they combine with it hope and positive thinking of their Lord, may He be glorified and exalted, the hope that He will reward them and honour them. Two things motivate those believing close friends of Allah to fear lest their good deeds not be accepted: thinking negatively of themselves lest they have not done well, and their great love for their Lord, may He be glorified and exalted. 
Ibn al-Qayyim (may Allah have mercy on him) said: 
“If he – i.e. the believer – is afraid, then it is more appropriate for him to fear that he is not doing good enough and what makes him feel that he is not doing good enough is two things:

Seeing his failings and shortcomings

The sincerity of his love (for Allah), for the one who loves sincerely draws close to his Beloved as much as he can, whilst feeling that he is not doing enough and that he is too embarrassed to meet Him with his deeds when he feels that He deserves much more.” (Madarij as-Salikin, 2/325)
To sum up, what you have to do is combine two things and do not omit either of them: 

Do not think of your sins as being too great in comparison to the forgiveness and mercy of Allah, may He be exalted. Rather what the believer fears is his shortcomings in repentance and his shortcomings in doing acts of obedience that expiate sins. So let this fear of yours motivate you to do more acts of worship and to ask Allah, may He be glorified and exalted, sincerely to accept your deeds and make you among those who are close to Him. Beware of despairing of the mercy of your Lord, may He be glorified and exalted. 
Think positively of Allah, may He be glorified and exalted, and hope for His forgiveness, blessing, kindness and mercy that encompasses all things. So long as you persist in obeying your Lord’s commands, respecting His laws and hastening to obey Him, you should also persist in thinking positively of Him and that He will accept it from you and make you steadfast in doing so. 

Al-Hafiz Ibn Hajar (may Allah have mercy on him) said, commenting on the hadith qudsi, “Allah, may He be exalted, says: ‘I am as My slave thinks I am’” (agreed upon): 
“Al-Qurtubi said in al-Mufhim: It was said that what is meant by “as My slave thinks I am” is thinking that one will receive a response when offering du‘a (supplication), and thinking that it will be accepted when one repents, and thinking that one will be forgiven when asking for forgiveness, and thinking that one will be rewarded when doing acts of worship, fulfilling all their conditions and believing sincerely in His promise. He said: that is supported by what he said in another hadith: “Call upon Allah when you are certain of receiving a response.” Hence one should strive hard in praying qiyam with the certainty that Allah will accept it and forgive one, because He has promised that and He does not break His promises. If he believes or thinks that Allah will not accept it and that it is of no benefit, this is despairing of the mercy of Allah, which is a major sin. If a person dies in such a state, he will be left to what he thought, as it says in some narrations of the hadith quoted above: “Let My slave think of Me as he wishes.” As for thinking that one will be forgiven whilst persisting in sin, that is pure ignorance and delusion, and leads to the view of the Murjiah.” (Fath al-Bari, 13/386) 
We ask Allah to accept your righteous deeds from you, and to make your Hajj accepted, and to grant you the best and greatest reward. 
And Allah knows best.