It's often said we are our own worse enemies. Reading and than rereading your post, I sense a real lack of self confidence, and possiblely a strong passive personality that naturally tends to deferance to others. Aviators seem to be populated by a lot of people strongly to the other bent, confidence to the point of arrogance. Pilots can be some of the worse at sniffing out (what they consider weakness) and helping to undermine confidence. If you have airmenship issues, as JohnBurke mentioned, you need to find a solution, maybe limit yourself to only one job/aircraft. I never felt I'd could do my best if I had to mangemet two aircraft at the airline level and took my hat off to my fellow crew who did both their airline and ANG jobs. That said, I think you are having issues taking command and being the boss. Being assertive is something your employer can't really teach but the job demands. You can read about CRM and how to deal with crew from either seat, but you need to figure out how to make good decisions, properly accepting imput from the sources at your disposial and follow though with confidence, even if other options were available.

You have dug yourself a bit of a hole, you know that. It is not going to be easy to dig your way out. You are your biggest critic and as such the biggest determent to your future sucess is getting out of your own head, develop a backbone, and not be looking over your shoulder at your past mistakes. I know from personal experience, fear of failure is real and the reaction to that feeling often causes the outcome to be bad. Look within, prepare, and believe in yourself. Good luck!