I would understand if the "not trusting" delivered an alternative for you, however, all it will deliver is uncertainty and that comes from fear.
Fear, is the opposite emotion of love....do you follow?
All anyone is suggesting you to do are trust in yourself. YOU, my friend, are the co- creator of your own reality.
What is there to not trust you about? Be clear and concise in what you want from the Universe, be convinced that you are deserving of what you are asking for, see it as done and let it go.
You say that the things that you want are "major changes" Well...it makes no difference to the Universe if what you want is a toy car or a mansion in the South of France, the size of the things we want has no bearing on your ability to co- create with the Universe...
Visualise what you want, talk about what you want, sing about what you want, write about what you want....and do it all in the present-tense, as if it has already happened.
Always visualise in the "now”.
Don't go about life as if you are going to get what you want....more precisely, go about life as if you already have what you want.
That is the key, trust in yourself, be very mindful of your thoughts and in the words of Mike Dooley.... "Thoughts become things, think the good ones”!!!!