optimize my google ads account for getting more leads

Hello we are using google ads since long time , since 2 weeks my ads performance came down amount also not consuming and leads also not getting.. when we feel leads day by day getting down one of my team members is tweaked few settings and ads & keywords and other stuff .. after that fully fall down .. now 1 lead or 2 max .. so some one can have very good EXP in google ads only please contact me