I think this requires an assumption that there exists on obligation to end our own suffering
The obligation in this theory is conditional on you wanting to end your own suffering. If you don’t care about your own suffering, then you have no reason to care about the suffering of others. However, if you do care, then you must also care about the suffering of others.
The obligation in this theory is conditional on you wanting to end your own suffering. If you don’t care about your own suffering, then you have no reason to care about the suffering of others. However, if you do care, then you must also care about the suffering of others.