Found after a long time I had made mistakes in my Salah

After a long time of praying, I realized I had been reciting the tashahudd wrongly so much so that the meaning had changed slightly. Do I need to start redoing all of my improper Salah now that I know about the mistake. I know unintentional mistakes and forgiven by Allah and accepted but now that I realize my mistake do I make them up or not? Please give references to your answers.