A page that exists to make new casinos easier to find has an obligation to say the other thing plainly: for some people the best new casino is none at all.
If you need help now. ConnexOntario offers free confidential support 24 hours a day at 1-866-531-2600 for anyone in Ontario. Every province runs an equivalent service, and the Canada-wide Problem Gambling Helpline network can direct you to yours. Gamblers Anonymous holds in-person and online meetings across the country at gamblersanonymous.org. None of these requires you to have decided anything in advance.
Signs worth taking seriously. Depositing more than you planned and doing it repeatedly. Chasing a loss with a larger stake. Borrowing to gamble, or using money set aside for something else. Hiding how much you play from people close to you. Needing to gamble to feel normal rather than to enjoy yourself. Opening an account at a new casino because the previous one has limits or a self-exclusion on it — a pattern this page's whole subject makes particularly easy, and one of the clearer warning signs there is.
Tools that work. Deposit limits are the most effective single tool and they work best set low and set early, before a session where you might want them higher. Most operators offer session reminders, loss limits, cooling-off periods and longer self-exclusion. Ontario-registered operators are required to provide these; offshore sites are not uniformly good at honouring them, which is worth weighing when you choose where to play.
Beyond the operator. Blocking software such as Gamban and BetBlocker covers gambling sites across a whole device rather than one at a time, which is far more robust than relying on individual self-exclusions — especially where new sites keep appearing. Many Canadian banks will also block gambling transactions on request.
For family and friends. Gam-Anon supports people affected by someone else's gambling, and ConnexOntario takes calls from family members too. You do not need the person gambling to be ready before you get support yourself.
Never gamble with money you need, and never treat it as income. If it stops being fun, stop.