He swore that he would never do a certain thing in his life, and stipulated that he would fast for thirty consecutive days if he did it, and if he did not fulfill that obligation, then he would fast for sixty consecutive days – and he has broken his
Question

                I swore by Allah that I would never do such and such until I died; these two things that I swore not to do are forbidden in Islam. And I added a condition to this oath that if I did either of these two things, I would fast for thirty consecutive days immediately after breaking the oath, and if I did both things, I would fast for sixty consecutive days. I stipulated these two conditions so that I would not break my oath, but unfortunately I broke my oath and I did not fast any of the days I had stipulated.

My questions are:

Are these conditions that I stipulated acceptable in Islam? I did not fulfill the conditions I had made at the time specified, so what should I do now? After breaking the oath, I committed this sin four or five times, so what should I do? Now I feel that I will never be able to fulfill those conditions and fast those days, so what is the solution? Is there an alternative to these conditions?
Praise be to Allah.
    
    Firstly: 

    This 
    condition that you stipulated in your post comes under the heading of 
    nadhr al-lajjaaj, a vow by means of which a person aims to push himself 
    to do something or to prevent himself from doing something. If he fulfills 
    his oath or his vow, then there is no problem, and this basically is what is 
    required of him, so long as he vowed or swore to do an act of obedience, 
    because obedience is either doing something obligatory that it is haraam not 
    to do according to the basic teachings, so he affirmed that for himself by 
    committing himself to do it by means of the oath or vow; or it is something 
    mustahabb (encouraged), so he is obliged to do it because of the oath or 
    vow.

    The 
    same applies with regard to refraining from something that is haraam or 
    makrooh (disliked). 

    If he 
    breaks his oath (yameen) and does that which he swore not to do, or he fails 
    to do that which he swore to do, then he has the choice between offering 
    expiation for breaking his oath (kafaarat yameen), or paying the penalty he 
    stipulated for himself in his vow. 

    
    Please see the answer to question no. 2587 

    Ibn 
    Qudaamah (may Allah have mercy on him) said: 

    
    Question: making a vow which implies an oath. 

    If 
    one makes a vow (nadhr) that implies an oath (yameen), in order to prevent 
    himself or someone else from doing something, or to push himself to do 
    something – for example, he may say: if I speak to Zayd, then I owe it to 
    Allah to perform Hajj, or to give my wealth in charity, or to fast for one 
    year – this is an oath (yameen), and the ruling on it is that he has the 
    choice between fulfilling what he swore to do, in which case he does not 
    have to do anything further, and breaking his vow (nadhr); in that case he 
    has the choice between paying the penalty he stipulated for himself in his 
    vow or offering expiation for breaking an oath (kafaarat yameen). This kind 
    of vow is called nadhr al-lajjaaj at the time of anger, and he does 
    not have to fulfil it; rather he has to fulfil nadhr at-tabarrur (a 
    vow to do some righteous deed). 

    This 
    is the view of ‘Umar, Ibn ‘Abbaas, Ibn ‘Umar, ‘Aa’ishah, Hafsah, and Zaynab 
    bint Abi Salamah.

    It 
    was also stated by ‘Ata’, Tawoos, ‘Ikrimah, al-Qaasim, al-Hasan, Jaabir ibn 
    Zayd, an-Nakha‘i, Qataadah, ‘Abdullah ibn Shareek, ash-Shaafa‘i, al-‘Anbari, 
    Ishaaq, Abu ‘Ubayd, Abu Thawr and Ibn al-Mundhir. 

    Abu 
    Haneefah and Maalik said: He is obliged to pay the penalty he stipulated for 
    himself in his oath, because that is what he vowed to do and he is obliged 
    to fulfil it, as in the case of nadhr at-tabarrur (a vow to do some 
    righteous deed). Something similar was narrated from ash-Sha‘bi.

    
     There is also a report narrated by ‘Imraan ibn Husayn who said: I heard the 
    Messenger of Allah (blessings and peace of Allah be upon him) say: “There is 
    no vow (nadhr) at a time of anger, and its expiation is the expiation for 
    breaking an oath (kafaarat yameen).” Narrated by Sa‘eed ibn Mansoor, al-Joozajaani, 
    in al-Mutarjam. 

    It 
    was narrated from ‘Aa’ishah that the Prophet (blessings and peace of Allah 
    be upon him) said: “Whoever swears an oath to walk (to the House of Allah), 
    or to offer a hadiy (sacrifice), or to give his wealth for the sake of Allah 
    or for the poor or as a gift to the Ka‘bah, then its expiation is the 
    expiation for breaking an oath (kafaarat yameen).” Also this is the view of 
    those whom we mentioned among the Sahaabah, and there was no one who 
    disagreed with them during their era; and also it is an oath. Therefore this 
    is included in the general meaning of the verse (interpretation of the 
    meaning): “Allah will not punish you for what is unintentional in your 
    oaths, but He will punish you for your deliberate oaths; for its expiation 
    (a deliberate oath) feed ten Masaakeen (poor persons)…” [al-Maa’idah 5:89]. 
    The evidence that it is an oath is that it is called by this name, and 
    nadhr at-tabarrur (a vow to do some righteous deed) is different, 
    because the aim behind it is to draw closer to Allah, may He be exalted, and 
    to do deeds of righteousness, and it does not imply an oath. But in this 
    case it does imply an oath, and it is not intended to draw closer to Allah 
    or to do a deed of righteousness. So it is similar to an oath (yameen) in 
    one sense, and to a vow (nadhr) in another sense. So the person has a choice 
    between pay the penalty he stipulated for himself or offering expiation…

    End 
    quote from al-Mughni (9/505). See also: Kashf al-Qinaa‘ 
    (6/275); ash-Sharh al-Mumti‘ (6/508) 

    
    Secondly: 

    If a 
    person swore an oath (or made a vow) then he broke that oath (or vow), then 
    that is the end of the matter; he only has to offer expiation once, and 
    whatever he does after that does not require any expiation, unless he swore 
    that every time he committed that sin, he would have to do such and such… In 
    that case he is obliged to offer expiation every time he breaks that oath. 
    But if he broke the oath several times and did not offer expiation each 
    time, then one expiation is sufficient. 

    
    However what you should bear in mind before swearing an oath or making a 
    vow, and you should focus on carefully, is the sin that you couldn't help 
    committing and concerning which your resolve was weak, and you have become a 
    prisoner to it. You must hasten to repent to Allah, may He be glorified and 
    exalted, from that, and take practical measures to avoid that sin, and to 
    close all doors that may lead you to it; you should turn to your Lord, may 
    He be glorified and exalted, and flee to Him. Turn from disobedience towards 
    Him to obedience, and from obedience of your nafs and your whims and 
    desires, to obedience towards your Lord. 

    And 
    Allah knows best.