K.P.
Contact your county social services office. You will likely qualify for "homeles" status which may entitle you to housing assistance and food assistance. Make sure that your school-aged children's principals are aware of the status change b/c there are regulations governing your children's records and supplies that may be available to them. The law is called McKinney-Vento and it makes sure that your children are not penalized in any way for your status and makes sure that their education is not disrupted.
Good luck... you have a lot you need to do in a very short period of time. Call social services immediately and set-up an appointment. It goes without saying that you two need to sit down together with the kids and have a serious conversation (on their level) about what is happening and the severe cutbacks in your daily lives that need to happen.