“You can be working endlessly for more than 7 years, but there is always light at the end of the tunnel and your time to shine will come.”
Related quotes

“There was no light at the end of the tunnel--or if there was, it was an oncoming train.”
Variant: He'd been wrong, there was a light at the end of the tunnel, and it was a flamethrower.
Source: Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch

Original: Quando provieni da un oscuro tunnel della vita... e passo dopo passo avanzi superando tutti gli ostacoli, all'uscita troverai la tua luce.
Source: prevale.net