Regression work
I think most people here seem to be missing the most effective form of hypnotherapy, hypnoanalytics, or regression work. Unlike in suggestion work, hypnoanalytics seeks to find the root of a problem in the subconscious, and either resolve the trauma, or address the ongoing need. It is extremely effective, and works with complex problems.
I have seen it heal depression, scoliosis, heart problems, social anxiety, arthritis ... I could go on. I'm not talking about little stuff here, I'm talking about things that are huge, life altering problems that have held people back for a long time.
It's the big gun of Hypnotherapy, and unfortunately, a lot of people are afraid to use it, because it can't be done solo, it's harder to do, and hypnotherapists have their own fears that they have to overcome.
But it really, really, works.
One problem that you will find, is that there is no licensure for hypnotherapy, and therefore, no regulatory agency governing who is allowed to practice, so you will have to do the research yourself on who is qualified, and who isn't, and just because they have a certification, doesn't mean that they are qualified. Many spend a weekend learning, and then call themselves experts.
Another problem that you might find, is that a lot of hypnotherapists like to pad their time with less effective methods, because if you fixed every problem in one or two sessions, you wouldn't make any money. Word of mouth seems great, until you realize that most people are so attached to their problems that you could offer them free help, and they would turn it down. Even people who have had huge success rarely believe that they can get helped with other problems.
If you don't have a lot of money, you might be able to find a hypnotism meetup somewhere in your area. They aren't always the most efficient people who attend, but you can usually get some free help, and sometimes get lucky with somebody who is willing to do good quality work for free, and you can learn some hypnosis in the process.
Good Luck.
-Andrew