It's hard to answer without triggering backlash in places like this, as the whole world of this kind of healing is a minefield of quackery and woo. It's taken me a long time to work through it all and be able to winnow out the practitioners and practices that are solid. And it's tricky to recommend stuff online, as some of it is linked to chiropractic (which I'm still not generally a fan of), and there are big-selling authors who have written multiple books about these topics, some of which is great, but some of which would be a dealbreaker for many.
Having said all that, if you're keen to research this stuff yourself, look up "Neuro Emotional Technique" and Psych-K, and look for books by Dr Bruce Lipton and Bradley Nelson.
But I'm happy to share more about my own experiences and practices if you contact directly. Email address is in my profile.