My doc said I have obsession disorder or anxiety disorder. But what if doc told me that because he thinks I have no problem in reality?

I am very afraid that my mistake I made when I was a kid could somehow get me cancelled from this society. I have been worrying about this for 3 months, more than an hour per day. My daily life is ruined by this. 

My doc said the worry I have is nothing and I have a disorder. But what if he said I have a disorder because he thinks my mistake is nothing, there were internet people who said that I am doomed, What if he said that just because he thinks my mistake is nothing?

If someone worries about something that has no immediate impact in her life, for more than 3 months daily, is it considered a mental problem no matter what she worries about?