This sounds like a 'confidence' issue to me.
Your nav is prolly no worse than the next guys.
Do your prep and planning properly and thoroughly and your nav will mostly work out ok. If you seem to be off by a bit now and then, try to think what trend is starting to show...early at a waypoint? or late.
Off track left or right?
Nav is one of these things that the more you do the less you need to sweat it.
Relax. Fly more if you can. Share your worries widely and shamelessly!
