Regression, simply, is an exercise in remembering. Our unconscious mind stores everything we have ever sensed. It is associated with the right side of the brain (the intuitive side of us) and works on a 'stacking-system'. That's why we sometimes repeat things to ourselves often, consciously, to help us to keep them at the top-of-the-list for easier recall from memory. Regression back by a few days, or weeks, months, and years - in this life - can clarify facts; can establish the cause of ‘triggered’ fears or phobias – to good effect.
Past-life recall is simply a case of remembering from further down the 'memory stack'. A registered hypnotherapist can help in this. Locating the fear and anxiety from past experiences - and achieving release of the fear(!) – allows us to move-on, with therapeutic benefit and far more confidence in ourselves - and in the future.