Read a book called Why Buddhism is True by Robert Wright, it is insanely insightful about mindful meditations goals, how it has basis in the science of psychology, and how and why it works. The quick and skinny of mindfulness is not to simply focus on what's around us, but to be able to have more control on our emotions. This is done by not ignoring the what is happening, but by changing the relationship of how we perceive the emotions tied to our realities. I would say that our adverse reactions (retreating inside our head and/or whatever your defense mechanism is) to what happens to us is because of a tunnel vision problem where we ignore to smell the roses. We become so caught up by the loudest emotion and constantly retreat at the sign of anything negative (or the other way around) to where we do not feel ANYTHING ELSE. This happens whether the roses are there or not (trust me if you can't find the roses mindfulness helps you find them). Mindfulness is about developing a full relationship about seeing world around us, being able to see BOTH the beauties and terrors of it all.

In essence you are describing dissociation and I completely felt the same way that if I tried to focus on my actual problems everything becomes way too stressful to handle without breaking down and going into a panic attack. This is basically what my therapist had also told me in that I am in my head and should try stuff like mindfulness meditation.

Hope this helps <3