High blood pressure last 3 visits to dr.?

dont remember the top number but the bottom was the first time 98 the second time 101 the third time 95 and he prescribed me dyazide 37.5-25 capsules and was told to take at night the first few days cuz it can cause dizziness, lightheaded, etc. then switch to morning with breakfast cuz can make you pee alot! lol.... is this a high or low dose cuz i am worried about the side effects...he also said it's likely my high blood pressure is hereditary, or cuz im going through early menapause and about to have a period for the first time in 3 months, so he said it could be a number of things. anyone know about this med?