The voices and the thoughts you mentioned are very normal, its something we all experience.
Your brain is constantly working, even when your just sitting down doing nothing, using an fMRI you would be able to see certain regions of the brains light up showing activity in those regions.
This is referred to as the default mode network (DMN), when your not actively doing a task, your brain without your control or even awareness wonders off and starts reminiscing about all sorts of things mainly all about you, your past and future, ironically the thoughts apparently are not the real you, and often times are just purely random, this region and its activity basically sums up your inner ego for better or worse.
Since most people aren't aware of this, they have no control over it. But There is plenty of scientific literature that shows that it can be controlled through two possible methods, meditation or taking particular drugs psilocybin aka magic Mushrooms, both lead to the same results. meditation in which you silence the chatter in the brain over and over again from my experience and as shown in numerous studies lead to more feeling of being in the present moment as there is less overall chatter in the brain, moments of pure silence, and oddly enough you feel like a complete different person, more aware, more empathic towards other etc. But this is short term gain as you have to do the meditation regularly.
otherwise you end up being controlled by the default mode network again, others cultures call this the monkey brain.
Taking certain amounts of the psilocybin just 1 time have been shown to lead to a reduction in the default mode network for much longer periods, also it has been shown to be better cure for depression then any other pharmaceutical drugs in the market
This potentially may sound like some hippy nonsense talk but there is lot of scientific literature to back it up, honestly I'm still learning about it and I would advise you to do your own research into this if your not already familiar with it.
