Fasting advice

(Hope im posting within the sub rules)

I decided to do the Monk fast (36 hours) as they call it. Started yst night 9pm and hope to break by tomm 9 am. I just had 2 cups of black coffee through the day just to down my hunger. Plus regular glasses of water. It’s night now and i had a cup of black tea about an hour back. Suddenly im feeling all nauseated and queasy sick. This is something new to me, so wondering if it is because of the whole day fasting? Is it normal? Appreciate if someone can guide me since im doing this to lose weight 🙏 thanks in advance!