my ob told me to get a shower chair because I always got dizzy and would feel like passing out so I…

my ob told me to get a shower chair because I always got dizzy and would feel like passing out so I got one and that went away I've had this chair for awhile and recently after my shower I stand up and both my sides hurt really bad?? is this normal is it kaiden not liking the way it feels I don't ever have it hot to where my skin is red nor pink soo I'm confused