Taking Temesta (Lorazepam) while water fasting?

Hello people!

I am currently on day 5 of my first water fast. I suffer from a couple mental issues and I have PTSD which gifted me with everyday hellish body tension which got worse over the last days. Now from what I read I explain this to myself with raising hormone levels on the first days of the fast, especially adrenaline in my case. I would really like to go on with fasting, however, I have an appointment next week which I couldn't imagine bearing while having this much anxiety. Can I safely take 1 mg of Lorazepam/Temesta to alleviate my tension and anxiety on that day? How will it affect the fasting process?