I'm so sorry you have this vertigo issue. I know how scary and frustrating it can be, as I personally know three people who suffer with it, including my sister. Each of the three has a different cause, but the result is that they all have attacks with no warning and have had to find a way to live with it.
Did you take the migraine medication? Did it help you? We have a section on vertigo: https://www.empowher.com/condition/vertigo.
The problem is there are several causes, they can be difficult to figure out, and even then with medication you may have to get used to it to a certain extent. For example, my sister goes through periods where it is bad for a while and then lets up a bit. So when she has been having a lot of trouble, she doesn't drive or do anything that could be dangerous with a sudden attack. When it slows down a bit she goes back to her normal routine.
If you haven't already, I suggest you try the medication. If it doesn't help or you don't like it, you don't have to take it again. But sometimes we have to balance between some side effects and being able to function. If you like, I can give you further resources. A site that may help you is the American Migraine Foundation, which offers support and information: http://www.americanmigrainefoundation.org/.
I know when this first started happening to my sister, it provoked some anxiety attacks. Now it is still unpleasant and frustrating, but she knows what it is and just deals with it. So eventually, if you have to deal with this long term, please know that it does get easier and you are not alone.
If you have further questions, please let us know. Good luck.