What action or supplication can be performed to ward off the evil eye and bad luck, given the continuous suffering from the unavailability of a suitable job and advancing age, despite performing Istikhara and avoiding sins?

Everything is by divine decree and destiny, and provision is in the hand of Allah. So, do not despair, and continue to strive through lawful means, while relying upon Allah. Increase your recitation of the reported supplications to facilitate matters. Among the means of sustenance are fearing Allah (taqwa) and maintaining kinship ties. For protection from the evil eye, fortify yourself with the morning and evening remembrances, Surahs Al-Ikhlas and Al-Mu'awwidhatayn (Al-Falaq and An-Nas), and supplicate with the specific prayers for this purpose.