Another day ,what to do when income decreases.

Any time your income is reduced, you have one of two options. The law allows for support to either be reduced or placed in abatement . This does require you to file a motion and appear in court. When you go to court be prepared to provide verificatoin of the reduction and the date it has/will take effect.
Abatement - Keep in mind that if your motiom is granted , what ever the support amount is it will build up as a debt to be paid back later.
Reduction is better if you still have some income or savings to draw from. Remember the child still needs and deserves support.