Hey, I know how you feel. A few years back when my ocd really started to surface, I had scary thoughts like that. I kept obsessing over why I was having them and what that could mean and they definitely got worse. I even started writing about voices in the same way you described.
What really helped was my therapist at the time assured me that I had ocd. I wasn't crazy or hearing voices, it was just ocd making me worry that I was. She helped me see that I am a good person, and i wrong intentionally harm anyone. People that hurt others don't worry about doing it. They like to do that sort of thing, it doesnt cause them intense fear/worry. People that hear voices don't worry they are/ might be hearing them. They just listed to the voice. Your brain is just trying to scare the crap out of you right now. You have to get to the point where you can say to yourself " wow brain, you are so creative, making me think up all these bizarre things. What a weird thought. " but then just accept that the thought was weird and MOVE ON. Everyone has weird thoughts like these. The problem with us is that our brain gets stuck on "why did I have that thought?" You are not your thoughts. Don't believe them. Accept them as thoughts and think about something else. Eventually you will give your thoughts less power and the worry of hearing voices and doing harm should subside.
Good luck. I know how hard and scary this is. You will be OK. <3

Sent from my XT1028 using Tapatalk