What is the ruling on retracting a vow that was coupled with an oath, such as saying: "My not entering Paradise," given the fear of not fulfilling it, and is an expiation for a broken oath required?

"It is not permissible to retract a vow after it has been made. Rather, it is obligatory to fulfill it if the contingent condition is met, unless the one who made the vow specified a certain period and it was not fulfilled within that period, or if he is unable to fulfill it with an inability that is not expected to cease. In such cases, he must offer an expiation for breaking an oath (kaffarat yamin (definition))."