It takes guys with a bunch of experience about 100 hrs in type to stop feeling uncomfortable and about 500 hrs, or one year, to feel really comfortable in type.
With 400 hrs TT you've got a tiger by the tail. Work hard and WATCH what your more experienced coworkers, be it CA or FO, do. Observe, study, be prepared, and figure out how to raise your game to their level. It will take time.
If you ever give up the tiger will turn around and bite you.
