Sometimes alimony can be modified. There are reasons for and against modification. It depends on your current circumstances and the language in your divorce agreement. You should consult with an attorney if you wish to modify alimony to get the specifics on your case.
As with any ongoing financial obligation entered as part of a divorce judgment, the only way to change an alimony order would be by way of a Complaint for Modification. To prevail, you would need to show a substantial change incircumstance from the conditions (i.e. income of either or both of the parties) that existed at the time of the divorce. And a voluntary or self caused reduction in income will probably not support the modification.