Kevin, you have all the classic symptoms of OCD. I have been in your shoes, thought those same thoughts, and yes they are frightning. But what you already realized is the thoughts and the person you are do not go together. You would never do those things that pop into your head because they are irrational thoughts.
In order to get out of the OCD cycle of irrational thinking that you are in, you really do need to see a therapist. I too thought, "how do I tell them I'm afraid I might accidentally harm someone I love? Well you know what I found out, there is absolutely nothing you tell them that they have not already heard before. Trust me on this! So make an appointment with a therapist that deals specifically with cognitive behavioral therapy. From there you can decide if medication is also warranted. Your life is waiting out there for you, you just need to seek professional help to get you there. You can live that normal life you want, I am proof of that!
I lost my mom and I too developed ocd but for me it is health related. I am soooo terrrified of dying of an illness just like my mom did. It interfers with my life and I have found it hard to live because of the sense that I am dying soon. Have you tried seeing a psychologist? Maybe someone who specializes in grieving and loss can help you. You need to let out all of your pain so that you can heal. Maybe you are angry on a certain level and that is why you have those thoughts. Losing a parent is life altering we love our parents so much and we feel safe when they are around, but when we lose them then the world looks like a total different place. Honor your dad by living a good healthy life think about what your dad would have wanted for you. Good luck.