Oryal, opinions and questions

Hello, I am a 23 year old woman who is being treated for hypertension and is taking cerazette as a contraception. I am aware that the tablets are diuretic. Since the heat is I feel very tired and drowsy. Could it be due to blood pressure (I read that in hot weather the pressure can drop) and drugs that have a diuretic effect? I try to drink a lot of water, but I have the feeling that the liquids pass through me very quickly. I plan to consult a cardiologist, but in my town there are unfortunately long queues for cardiologists. Is there anything in the meantime that I can do/take in to improve my well-being? Not counting drinking plenty of water and resting?