A lot of times, in a lot of situations, having "ammo" against some of the intrusive thoughts doesn't help me - but for some reason, in one particular situation you're describing , it helps me a lot.

In the case of getting grabbed:

Think about your surroundings and possible escapes when you feel unsafe -you can go into shops, restaurants. Also, the fact that there are cars and people walking is in itself going to deter some maniac from grabbing you - it's too crowded and you can shout to the others.

Think about the fact that you are going to make good decisions while you are on your walk - you know your route, you know to avoid a certain area, you know not to get into a car with a stranger, you know how to be alert, you know when it's ok to cross the street, etc. These examples may seem like extremely obvious decisions anyone would make - but the sad truth is many don't make these decisions - and they are far more likely than you to be victimized.

Think about the strength within you - you could defend yourself should you need to. (Poke em in the eye, bite em) My friend, a physical trainer, gave me a simple but very informative lesson in basic self defense that really empowered me. There are many such classes in all communities. I've even seen single session classes that are sometimes free or otherwise very affordable. I highly recommend it. It's such a boost.

For mental defenses, search and follow good advice from others but you should also think of other things and examples on your own that will give you strength against that sort of situation and also against having negative thoughts about that sort of situation in the first place. I could give you countless more examples but that's counterproductive... I find that when I can come up with my own ideas, I'm more empowered in some way - because I was able to find the strength within myself.

With OCD, your mind is constantly running. So if you're sitting at home and you start thinking about the outside scenario, carry that thought further than just the fear part of it - build reasonable defenses against the idea.

This is important: sometimes when the negative thoughts happen, it is super easy to get completely caught up in the ideas that your mind is force feeding you and you might forget all your prepared defenses. It's good to have a clever reminder, even a visual cue somewhere, so you can remind yourself to try and conquer the mental threats as they happen.

Prepare for the world outside and still be vigilant and be safe and plan your route. But when your mind starts to unreasonably attack you with this negativity, take out your "ammo" and use it against the constant threat that your mind is putting you under. Fear can be a good thing, it causes adrenaline that will help you to think and act quick in an emergency situation. It's just not good to be under constant fear with a constant adrenaline rush.

Building your own defenses wont happen over night, it takes time, it takes "test-walks". I'll even sometimes forget my own defenses on occasion - it happens, we all have bad days. Sometimes on a walk I'll be thrown a sort of unexpected "curve ball" that I hadn't anticipated. A couple months ago, in broad daylight, a drunk was walking next to me and shouting some pretty crude things. I was very worried that it might escalate to a physical fight. It was a minor setback for my sense of security, but since I already had some mental defenses planted in my head, it was easier to build newer defenses and get over the event quicker. I'm much better prepared mentally to take on the walk than I ever was before. You'll get there sooner rather than later.

I really do know what you're going through. Having said all that, there are still other places and situations that I still have an intense fear of intruders and bad people. OCD is like fighting a war. But I battled the walk and I won.

I hope this helps you some, even if it helps just a tiny bit. Baby steps.