I've actually been going through this same thing. It all started with a mountain of trauma and continues to baffle me. I also believed in thought broadcasting, which is terrifying, but I've debunked it. What I've learned is to reality check everything. If you need to know if a voice is real, use your phone to record video and compare.
People don't have all day to talk just about you, so start to think that anything you hear about you is within your own mind. Once you've realized it's all thoughts, then you have the ability to quash them. Imagine your minds eye as a browser page. Keep hitting ctrl+w until you land on a page/thought you find acceptable.
Asking other people general questions about what they see and hear is super important. Just be careful how you broach the topic so they don't create trouble for you.
You're extremely strong to endure this. Stay strong! The good news is, once you get treatment, you'll be able to dispense with OCD as if it wad nothing compared to the hallucinations.