Why did my air conditioner start blowing only warm air?

Suddenly my air conditioner is only blowing warm air. I checked the unit inside the house, it is working and I changed the filter. The unit outside is also working, but all of the air is room temperature so my house is like a sauna. I am wondering if I need a freon charge. The thing is that I really don’t have the money to spend on a repairman. Any suggestions?

A couple of more things that might matter, both units seems to be blowing out cold air, but neither seems to be directing it toward the ducts. And, the day this started there was a message on the thremostat that said RE CO, according to the instruction manual that means that the unit was in “recovery mode”. I have no idea what that means though.