My furnace is flashing for the limit switch open and it won't stop blowing cold air! I have 2 kids and need the heat asap!

You have to find out why it's tripping the hi-limit. It will not just go out without a reason; either the fan is not blowing or you have a bad limit switch. Reset the limit and see if fan is not working. There is a switch on the fan switch/hi-limit combination switch that you can pull out to turn on fan manually.