How do you hold to no preference when an outcome obviously seems desirable? Making money vs. not? Being happy vs. not?
Being with the unhappiness, and then letting go it, will change the state of being. States are transitory. Everything is transitory.
Accept, acknowledge, let go.
Being present should eventually cause transition to the new state of being. Emotions are internal manifestations of events, not the events themselves. Thoughts are internal. Feelings are internal.
Sitting alone in a room won’t make you upset. What you think and feel in that moment may cause you unhappiness. But nothing in and around you is making you unhappy. You can acknowledge the feeling, and then try and let out pass from you naturally.
Accept. Let it go.
If this is difficult, turn your attention wholly to your surroundings, or, in a meditative way, to your breath. Focus on the sensations.
That is being present, and that is one path to non-preference.