Is it normal for those with postural hypotension to go blind for a few seconds after standing up?

I went to two doctors and my psychiatrist and was told that I have postural hypotension. I would like to know what can I do when I get dizzy and have a temporary loss of sight. Is loss of sight normal for postural hypotension? The doctors don’t seem to help. I was told to drink more water and eat better and get up slowly. I can’t do that when I have to pee at night. (I’m literally peeing blind).