Ask about dehydration and sugar, too.
I get vasovagal response many days (it's just a fancy word for unexplained dizzy spells). I often can help myself by making sure I get enough water in a day (and not coffee or alcohol, sorry, as they both dehydrate you) and sometimes sugar.
Of course your doctor is the #1 go-to for you. But those might be at least a part of it.
I know a lot of how you feel (e. g. spinning bed, how nice. Not.). Hang in there.