Hello there. I don't get your concern. You feel a need to breathe deep and it has become severe since you stopped smoking? See, it's normal to feel the need to breathe in deep once in a while. Normally, smoking would cause your lung capacities to decrease by damaging the lung. But since you stopped smoking, you should be able to see a difference and improvement in the lung functions. Don't have to worry. You have done a great job by quitting smoking, But just don't start smoking again. Regards