It sounds like your nausea may be lasting longer than is common to PCS. Have you tried eating ginger snap cookies in the morning? They (the ginger) have great anti-nausea properties.

As far as how long your PCS symptoms will last, there is no rule to go by. Every concussion is different. Comparing just makes people more anxious. I suggest you take it easy and rest and try to be patient.

My best to you.