I'm stalling out

If the car is in neutral it idles. In any other gear it's idle fluctuates alot and it tries to die. It's like its making the transmission drag. We replaced one of the fuses and it ran fine for three days. After that fuses didn't help. Alot of the times when you go to put it in gear it just dies automatically. When I let my car just idle in park it goes dead even at redlights I have to put it in neutral and keep a little pressure on the gas to keep it running.