Can I stop Cymbalta with no problem after 6 days?

Hi, Neebebe!
The answer unfortunately is maybe. Most likely you won't but some people who are very sensitive to the drug may experience some discontinuation symptoms.
Have you let your doctor know that you're having these serious side effects? It may be that a dosage adjustment might help or you may need to switch to another medication.
I know it's the weekend but I suggest you try calling your doctor or the doctor on call for their professional advice. At very least, first thing on Monday morning.
Best regards and I hope you're feeling better quickly.