I have made an oath to refrain from repeating a sin where I swore that everytime I repeat I must pay $Y to charity. Although after a while this became a high load which will put hardship on me to pay and I won't be capable to fullfil it due to needing the money.
1. Is the oath still valid?
2. If the oath is not valid due to these circumstances and at a later date I become capable must I fulfill the oath?