You need to petition the court in which you obtained the divorce. If that court no longer has jurisdiction for some reason, petition the court in the state in which your ex spouse lives but start with the court that issued the initial order. Explain your situation and that it has become a hardship for you and you can no longer sustain the expense. It may be more likely that you will get either the alimony cancelled entirely or you will be able to get it significantly lowered. If the lowering doesn't work and you don't obtain a cancellation, consider talking to an attorney about other financial alternatives for you and your current spouse so she is protected in case anything happens in court regarding your assets.