If I ask to have my order changed, will the amount decrease?

Not necessarily.

If your financial situation has improved, your order may increase. If you’ve lost your job, your order will probably decrease, but it depends on your overall income and some other factors.

The reviewing authority (court or administrative officer) will decide if there has been a "substantial change in circumstances" and will make the final decision. In many states, the support amount must change by a certain dollar amount or percentage (10% to 20%) for a modification to be issued.