I think you would have to be more specific really, we all have bad days I suppose. Was it a screw up on the approach that left you unstable, or was it more like forgetting stuff on checklists........
At the end of the day, we are all human and prone to mental and physical errors.
It sounds by your post that you are beating yourself up about something. Thats fine, but keep it in a healthy reality. You have 2000 hrs experience and that can't be taken away from you.
Treat each day as a learning experience, I think most PPRUNER's would agree that we can all learn something new every time we fly, regardless of our experience levels.
Cheers.