Finding the Why behind the Why

I’ve come to the point of taking responsibility for sometimes being (ungraciously) confrontational with people (bosses) in authority.
This appears to be a contributing root cause of a number of serious challenges I have faced in my career.
Asking myself “Why do I choose to be confrontational?”, I come up with I’m angry, frustrated and/or insecure (paranoid that they don’t like me, etc.).
1. Is my next step to figure out WHY I’m angry/frustrated and insecure?
2. What should I do if I get stuck here … I can’t put my finger on WHY (other than the catch-all “my parents messed me up”)?
3. Is there a module in the Study Vault or series of Podcasts that you can recommend to help me figure this out?
I want to take responsibility and rid myself of this ineffective coping “skill”. Thank you.