Thank you for posting these thoughts and observations to the forum. When guilt (and/or shame as hucky2311 alluded to) is involved it can be difficult to want to share these experiences however I feel it is really important that you have.
I agree with those that have already replied, that you do not need to feel responsible for the decisions of another person. You were only doing your best with the best knowledge you had at the time. No need to feel guilty. I have had numerous teachers tell me the answer is just to “try harder” or that “I wasn’t trying hard enough”, which is clearly an imbedded part of brass playing psychology, and a reflection on brass playing psychology itself and not you.
Without making a mountain out of a molehill, to keep “trying harder” essentially leads to fighting the instrument and being hard on oneself. The word ‘fight’ is synonymous with the engagement of the sympathetic nervous system (fight/flight/freeze) which is also triggered by the guilt/shame response. This situation reflects an incorrect understanding of the physics/acoustics of the instrument in the general brass playing world and a lack of awareness of the psychology of learning. To remedy this, one has to move themselves out of fight/flight/freeze and this is why the further through Windworks I get the more I realise the most important exercise is just to find calm. ie meditation.
Thank you Wellsweb62 for starting this thread. I would love to hear other’s thoughts!