Assalamu Alaikum
Inshallah someone will find a fatwah for you, in the meantime I'm going to mention a few things that I already know about oaths.
When you make an oath, it should solely be made to Allah. So to swear on your belongings, family, etc. is considered shirk and not permissible.
If you make an oath unintentionally, then it doesn't count, but your oath sounds intentional so you should try your best to fulfill that oath (as long as fulfilling that oath is not haram). So, to expiate for an unfulfilled oath, Allah says:
“Allaah 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), on a scale of the average of that with which you feed your own families, or clothe them or manumit a slave. But whosoever cannot afford (that), then he should fast for three days. That is the expiation for the oaths when you have sworn. And protect your oaths (i.e. do not swear much). Thus Allaah makes clear to you His Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) that you may be grateful”
[al-Maa’idah 5:89]
So basically, if you can afford to, feed/clothe 10 poor families to the same degree that would fulfill the needs of your family (I believe you can do this over a period of time, not all at once, but I'm not 100% sure about that), and if you can't, then free a slave (I'm sure you don't own a slave

) and if you can't do that, then fast for 3 days. You should also do some repentance and be more careful when making an oath.
Finally, don't wish death upon yourself for something trivial or worldly. It's only permissible if you're in a situation where death is better than falling into a severe sin.
fi aman allah
w'salaam