I am finding it increasingly difficult to fast the entire Tisha B’Av and Yom Kippur. I’m 50 years old but haven’t fasted the minor fast days since the years of pregnancy/nursing because not only do I have to stay in bed all day, I’m sick for 2 days afterwards. During the fasts I am dizzy, sweaty and increasingly nauseous enough to projective vomit. I definitely can’t make it to shul; I’m afraid I’d pass out. I think I could make it to chatzos on the big fast days but to fast an entire day, until 7 or 9 PM, I’m just so sick during the fast itself and as I said, for 2 days afterwards.
Your status is certainly that of a choleh, and you are therefore exempt from minor fasts. Even for Tisha Bav such extreme illness may exempt you. Yom Kippur however is a Biblical obligation, and must be kept even in the event that it will make you sick. This is as long as it poses no danger or risk of danger to your life, meaning ‘pikuach nefesh’. There are various methods to make fasting easier, which include taking various forms of medicine, either orally or with a suppository. On Yom Kippur even if you need to stay in bed the entire day and not daven at all this is the proper thing in order to fast, as that is our prime obligation on this day.