Dear aaaaAAAHHHHH,

Obviously the event that happened years ago with your grandfather made you extremely worried about protecting yourself (and with good reason). This fear/anxiety grew into a obsession for you because it had a traumatic effect on your life. Now the obsession is making sure you are safe and that unwanted people cannot get in.

Your 'checking' the doorknob is classic OCD but the fact that you were abused as a child adds another element to the picture. I would strongly recommend you seek out a counselor or therapist to share your fears, concerns and past with, especially the piece about your grandfather. Even if people feel they have gotten over a traumatic event like that, they still carry the weight of what they endured. Just dealing with what you went through will be so beneficial for you. I would expect your anxiety to decrease and hopefully some of your compulsions too! Good luck!