Your experience resonates strongly with my own.
For me, neijia, neigong, and neidan are journeys of self discovery.
A teacher can give pointers and direction, as well as exercises to engage with, but we must engage and discover for ourselves the true meaning, proper technique, and results.
Externally, the teacher can adjust the posture but internally, the inner details of posture must be discovered.
This is the only way we can learn to self-correct and make meaningful progress in our practice.
Once we have developed adequate skill and confidence, engaging with others allow us to test our progress and discover our weaknesses and errors, such as in tui shou, san da, and so on.
This is why it is said in taijiquan that we must 'invest in loss.'