Originally Posted by CobaltFortune
Does anyone know what this problem is and how to fix it?
That's 100% normal :)
Even if we don't have any problem, our mind works just like that, we have random thoughts coming all the time.
There are now countless guided hypnosis sessions available for free on the internet, I would recommend to try many and see which ones work best for you. You may be more receptive to certain techniques, or people.
Then I think you'll be more able to go under hypnosis by yourself.