Maybe you just need to study a bit about communication skills. Good luck...

Developing good habits, never stop learning, reading about one's field and working both hard and smart :)

The trick is to harness healthy daily habits as opposed to destructive habits to create a positive climate in your marriage. And these habits don’t have to be grand gestures or sweeping changes.

You could have an underlying anxiety issue; you have learned to cope with using nail biting to expend the additional energy and allow for stress release. You should look into what triggers your anxiety and nail biting habit.