Generally such habits are a way to contain anxiety. It’s a creative solution. This habit of yours started as a way to help you settle down and focus. Unfortunately the very thing you created to help you be less anxious is now making you anxious.
The counting has gone too far. Clearly, you can’t stop to tap every time you make a jump without intruding on the grace of your program. You can’t count on getting the fourth seat. If you are focused on counting while walking, you could bump into walls. You need to get back in control of the habit — and the anxiety that is behind it.
I suggest you make an appointment with a mental health counselor who specializes in treatment of anxiety disorders. The root of your problem is anxiety. Learning some new and more effective coping skills may be all you need to give up the habit — or at least to keep it in bounds. If not, the therapist will talk with you about options for managing OCD.
There are medications that are helpful as well as other anxiety-reduction techniques. I’ve taught self-hypnosis, for example, to a number of young athletes who were then able to marshal their own inner resources to relax in competitions.
I wish you well.