The ruling on one who vowed to perform several acts of worship if her distress was relieved, but was unable to do so

Q: I am a young man of twenty-six years. Allah has subjected me to one of the trials of life that befall every young man. I am married and have three children who live under my care, after Allah, and my mother is advanced in age. Divine decree has prevented me from seeing them for approximately one year and six months. So I vowed to Allah that upon my return to my home and my children—who, during my absence, came under the care of the charitable—that I would fast six days for Allah the Exalted, slaughter two sacrificial animals for Allah the Exalted, and visit Makkah and al-Madinah with my father. I would also carry my mother on my shoulders and perform the circumambulation and the sa'y with her. When that trial passed, and due to my poor financial condition and that of my family, I slaughtered only one sacrificial animal and was unable to bring the other. Likewise, I was unable to take my family or my mother to Makkah and al-Madinah to fulfill my vow, due to my poor financial condition. I was even unable to perform the fasting. Fearing that I would fall into sin and burden, I sent my message to find a solution that pleases Allah.

A: Praise be to Allah who has made it easy for you to reunite with your parents and children. We ask Him, Glorified and Exalted is He, to rectify your condition, all of you, and to help you in what He loves and is pleased with. As for the vow, it is obligatory for you to fulfill it according to your ability. Allah has praised the believers who fulfill their vows in His saying: [Al-Insan:7]. And the Prophet (peace and blessings be upon him) said: narrated by Imam al-Bukhari in his Sahih from Aisha (may Allah be pleased with her). So you must perform the second sacrifice when you are able, due to His saying, the Exalted: [Al-Baqarah:286], and His saying (peace and blessings be upon him): [Al-Taghabun:16]. So whenever you are able and what you need to buy the second sacrifice becomes easy for you, do so, slaughter it, and give it in charity to the poor, unless you intended to eat it with your family, in which case you are to follow your intention, due to the saying of the Prophet (peace and blessings be upon him): agreed upon by al-Bukhari and Muslim.
As for if you vowed the slaughter but did not intend to eat it with your family, then you give it to the poor. And you must fast six days, because it is an act of obedience to Allah, so you must fast them whenever you are able, even if they are scattered, unless you intended to fast them consecutively, in which case you are to follow your intention, due to the saying of the Prophet (peace and blessings be upon him): If you intended to fast them consecutively, fast them consecutively.
And you must also perform Hajj with your parents and take your parents to Makkah and al-Madinah as you vowed. If you intended 'Umrah, then it is 'Umrah; if you intended Hajj, then it is Hajj, according to your intention, whenever you are able: [Al-Baqarah:286]. And He says, the Exalted: [Al-Taghabun:16].
And you must also take them to al-Madinah, because traveling to al-Madinah for the purpose of praying in the Prophet's (peace and blessings be upon him) mosque is a recommended practice and a nearness to Allah. And if you visit al-Madinah, greet the Messenger (peace and blessings be upon him) and his two companions, and this is the best for you. Visiting his grave (peace and blessings be upon him) and the graves of his two companions is prescribed for those who are in al-Madinah. Likewise, for men who travel to it. What is forbidden is traveling solely for the purpose of visiting his grave (peace and blessings be upon him). As for traveling to the mosque, and the visit is included in that, there is no harm in it. And greet the Prophet (peace and blessings be upon him) and his two companions (may Allah be pleased with them both). As for women, they do not visit graves. But you, your father, and the men with you, as for women, they do not visit graves, but they pray in the Messenger's (peace and blessings be upon him) mosque and send blessings upon him in the mosque, in the houses, and on the road (peace and blessings be upon him and his family). It is also prescribed for you and the men with you to visit al-Baqi' and visit the martyrs. All of this is prescribed for men. It is also recommended for you and the men and women with you to visit the Mosque of Quba and pray in it, because it is a noble mosque, and visiting it and praying in it is recommended for those who are in al-Madinah and for those who travel to it.
As for carrying your mother or your father when you perform Hajj with them during the circumambulation and the sa'y, there is no blame on you in that if they are unable to walk in the circumambulation and the sa'y and you are able to do so. But if they are able, then they must perform the circumambulation and the sa'y themselves, and there is no harm in their performing the sa'y while riding, like the other pilgrims and those performing 'Umrah. The matter in that is broad, and praise be to Allah. As for carrying them, it is not obligatory for you to carry them due to the hardship involved and the lack of evidence for its prescription.
And you must expiate for this vow with the expiation of an oath if you do not carry them. It is feeding ten poor people or clothing them, giving each one half a sa' of dates, wheat, or rice, or clothing each one with a garment that suffices them in prayer, such as a shirt or an izar and a rida. And it is not upon you to carry them, but they perform the circumambulation and the sa'y themselves—as mentioned before—if they are able. But if they are unable, they are carried for the circumambulation and the sa'y, and praise be to Allah.
And we ask Allah to help you fulfill your vow, and to accept from us, from you, and from all the Muslims. We advise you not to make vows in the future, because the Messenger (may Allah's prayer and peace be upon him) said: So we advise you in the future not to ever make a vow. Whenever a blessing befalls you, thank Allah for it, obey Him, and praise Him, and there is no need for a vow. And you said in your question: "But divine decree prevented me." The best is to say in such a case: "But Allah decreed such and such," because the fates have no power; only Allah has power. So you say in such a case: "Allah decreed upon me such and such" or "Allah willed such and such," so you attribute the matter to Allah (Glorified and Exalted is He). And success is from Allah.