This is what I practice the most in rehabilitation. You must be mindful of your body and the signals that are being sent. Use your senses and simply observe.
Being present and observing what your embouchure is trying to tell you helps navigate throughout the complex symptoms so you can find and reduce areas of tension in order to start working on reprogramming your motor skills and regain sensory feedback.
Being aware of your body in a mindful way is not a negative thing! Your mind can't be focused on negative thinking (i.e. the way things "should" feel, the way things "should" sound, the way things "should" look), and equally it also can't be focused on musicality or just playing "through" things.
When your symptoms are severe, especially during the height of embouchure dystonia, you're not at a stage to even start doing that. If you do, you risk getting a secondary injury on top of your disorder. You can't force things, so it makes sense why a musician with a disorder or injury can't be focused on normal playing methods or tactics (i.e. focusing on phrasing, tone color, breathing, mechanics, technique, singing through or playing through things).
You must be aware and in the moment. Be fully present of what is happening and not panicking. Observing (I like to use the word "exploring") where you actually have functional brain signals being sent and helping those areas bleed over into the unstable areas of your dystonia (sounds easy but believe me it's not!)...this is where you find leverage and begin regaining your playing abilities and a sense of dignity.
This is what I mean when I talk about changing your mindset so that you can start focusing on what is really important - the neurological/physical symptoms in your playing.
If you are lost in the realm of emotions, musical-esque notions, expression, or advice of others who don't have the disorder, it's going to be impossible to see any major progress (unless you are 98% recovered already and can focus on that type of stuff).
If you struggle with focus, one way to engage mindful observation is to just breath and empty your head by listening to the white noise in the room, listen to the clock ticking on the wall, feel the sensation of your feet touch the carpet. Then try to visualize blowing on hot cocoa and start playing (or mouthpiece buzzing or freebuzzing). Remember you are simply observing and exploring what your dysfunctional embouchure is telling you....really get to know its tendencies and reflexes, even if sometimes you can't get a seal or sound out at all. Keep noting your observations. This will help you later with adjustments and modifications as you go along.
If you can learn to love the act of doing this and accept your sound and state of disability in a hopeful-survivor and explorative type of way, that's going to take you far in recovery.