Sadly, time doesn't work that way.
And disease doesn't work that way.

But, it is a good theory based on our current popular beliefs about time and disease.

The reality is that your universe ends a half inch away from your out stretched finger. And, in your universe exists your pasts and your futures. So, visiting the past, or the future all exists within your timeline and anyone else that chooses to interact with it.

First, let me tell you that going to your past to "fix" something doesn't work. You have to heal it energetically. You have to change who you are "now", and this will change both your past and your future. And, it will make your mind hurt for a while, that the get in touch with your inner child meditation ... well, your friends/family remember the new story.