How long does it take to adjust to prazosin?

I started 1mg prazosin last night and didn’t sleep super well. I didn’t have nightmares but still couldn’t really sleep. I tried to go to the bathroom in the night and barely made it without passing out. This morning I feel super weak, having cold sweats, and still lightheaded. Has anyone else felt this? How long does it take to adjust? Does it get better?