Hi Daniel,
Chag Sameach....
I been at this a bit longer than you so I will give you the long and short term advice.
I made it a point to be as 'normal' as possible once I had my k pouch done (same pouch, different exit) which included doing all of the Fasts (there are in all the worst being a 26hr one in mid-August)...being young and stupid and not having this site to help me I did not follow any major rules other than eating a good meal and drinking well.
I would try whenever possible to sleep late the next day...take a nap if I needed it and break the fast with homemade lemonaide and chicken soup.
I did great...Each time...But, I would be suspiciously ill for the weeks that followed and did not understand it.
Thanks to a lot of people here I now understand that I threw my body into major dehydration which is dangerous and can cause long term problems.
So there are some rules that you need to follow.
You need to hydrate well throughout the day (today) and have enough salt (try good homemade chicken soup) and fluids to hold you through most of the day...
Lots of homemade lemonaide (lots of honey or sugar if you are not diabetic in which case you should not be fasting at all) made with fresh lemons and a handful of mint, white grapes, no fatty foods or too much oil, potatoes cooked, steamed or mashed and no salads or raw veggies.
IF you start to get a bad headache, feel dizzy, start having cramping, diarreah or nausea, aches or pain anywhere then Drink! Not just water but lemonaide or chicken soup (or both) It is not a sin to break the fast if you have a medical condition. You are even permitted to drink a 1/2 glass of fluids and eat 25gms of solids in the morning if you are ill and still be considered as fasting.
You are not permitted to cause yourself harm so fast smart and be vigilant.
Chatima Tova
Sharon