It’s fine to use more than one  session in a day. If you are drawn to repeating a session that’s fine too, in hypnotherapy we call that compounding ie. reinforcing. It is also ok to use two different sessions in a day. Just be aware of your emotional state and go with what feels right for you. We would recommend 2-3 sessions maximum in a day as you need a little time in between to assess how you’re feeling and what to focus on next.