There is no key and no lock to control once you get addicted.
If betting is your Full time job then have good amount of money in hand, Stick to very few sports (Not Fantasy sports). Spend time on the different sites for few days, analyse the odds before the start and end of the games, then start betting in small amounts, and analyse both win and loss, and continue slowly.
If lost completely one day stay away from the site for a while and start fresh. Set some goals and limits and don’t go beyond those limits.