pascha bchochma; drink plenty of water, and poweraid.
Eat complex carbohydrates right before the fast,
I personally suggest you eat some pastaand whole wheat bread.
Then right befor the fast take two tablespoons of honey.
That should help you fast well. Hatzlacha.
P.S. towards the end when you’re getting weak, you should lie down to rest. You don’t have to be in shul the whole day, if your a woman. After you have davened for mercy and regretted past deeds,
and done teshuvah, the ikar is to be M’uneh.
that is done by fasting, So you can go home in afternoon to rest.
I wish all of klal Yisroel a meaningful, healthy fast.