Generally, spousal support can be modified only if the decree or agreement included language reserving the court's jurisdiction to do so. If the court finds that spousal support is justified, it must determine reasonableness based on statutory elements.
You can think of following options: File a case in court for abandonment by husband. You can also seek for RCR (restitution of conjugal rights) as your husband has left you. You can file a case for abuse against husband for causing mental torture by deserting you.
The separation agreement shall provide for a division of all property; spousal support; if there are minor children of the marriage, the allocation of parental rights and responsibilities for the care of the minor children, the designation of a residential parent and legal custodian of the minor children, child support ...
Rather, a court may award reasonable temporary spousal support to either party during the pendency of any divorce or legal separation proceeding. Courts are not required to award spousal support. There may be situations when a court finds that spousal support is unnecessary.