You sound much like me many years back. I had a baby at age 24, and a month after she was born, right out of the blue, I suddenly got so dizzy and the room started to rock like I was on a boat in very choppy waters.
Freaked me out - thought I was having a brain aneurysm or a tumor or who knows what? It was really, really scary.
I had several different diagnoses before finally hearing I had MS. The list? Dehydrated, inner ear disease, and oh, my favorite - hyperventilating because I was a nervous new mother.
I KNEW none of those were right - this was some serious equilibrium problem that I'd never had before - but for some reason, when you're young, they have a hard time taking you seriously.
I wish you well and if it does turn out to be MS, know that medical science has come a long way since I was diagnosed - back then there were no drugs to treat it like there are now. Your chances of being OK are very good - keep looking for the answers you deserve.