How can I show or prove to a man that I’ve healed before starting a new relationship?
The only person you ever need to prove to that you have healed is yourself. If you are healed and open for a grounded and mature relationship, this will be obvious from the way you speak and hold yourself. No one will ever need to ask you to prove anything, and nor should they. The question for you is, how can you feel confident within yourself that you have healed? Once you do, the rest follows naturally.