Withdrawal symptoms can last for months, years, or even become permanent. Insomnia, depression, anxiety, agitation, all kinds of mental symptoms can occur after quitting and must be treated by a professional. Trying to do it on your own is usually a recipe for failure
Yeah man, once I was in a similar situation once and my manager said something like ' I'm giving you another chance out of respect for you. Now show me respext by getting it together.'