Wow, you are doing great for never fasting before. I'm also on my first fast, unlike you I was hungry for the first few days. I can't answer your question regarding the nausea because lucky for me I haven't had that, I have read that some people get that further into their fast than you are and I would say that it is normal.
If you will check out this link it will give you great information on fasting, also later tonight I'm sure more knowledgeable people can answer you questions.