There are NO LIMITATIONS to what you can achieve if you put your mind to it.
That's a fairly dangerous assertion.
I too am a qualified hypnotherapist and Master of NLP.
I find that, in application, NLP can be fundamentally flawed when it takes this approach.
Hypnotherapy is, in a way, a form of trickery that requires the body to catch up.
So, if you are looking to 'grow' your breasts, no amount of auto-suggestion will cause them to grow 'like magic'.
What may happen, in fact, is that your breasts grow as a result of a change in diet or lifestyle, the resolution of a pattern of illness, perhaps even a pregnancy.
The approach of 'as i think, so it is' is mechanistic - that is, based upon a simple model of cause and effect.
As i mentioned in another post [this one in regards to 'the secret'] the idea of cause and effect is too simplistic to address life in all its complex, contradictory and chaotic magnificence.
it is a model that we use nowadays as part of a strategy of 'getting what we want'.
if hypnotherapy could help you to achieve ANYTHING, i am sure there are plenty of amputees out there who would be happy to organise a few sessions for limb replacement.