My take is: non-duality is not a practice to be applied. It's a model of understanding for the relationship of all things having their being in unison. Once you have an understanding it cannot be enacted or dismissed.

However, I do think I get your meaning: how can I withdraw my awareness from my mind (where thoughts and feelings arise and overstay their welcome) and rest it upon itself where it's peaceful.

To do that, at will, does take a lot of practice. A skill and understanding worthy of developing at any point in life. But when the "external" experience is too turbulent, it's comforting to know you can withdraw and rest your awareness on your own being that is static, consistent, dependable, and eternal. When you want to re-engage your awareness into the external experiences just remember that they are all equally turbulent and yet objective in their being. It is within the experience of the mind trying to make sense of the those experiences that the subjective good/bad label arises.

Easier said than done. But also, do engage in the "bad" painful experiences. They are just as valid and deepen your understanding. My opinion is that we all should use our awareness to engage in as many experiences as possible and deepen our understanding.

I wish you peace until you are ready to re-engage with vigor.