Every legal (online) casino in the Netherlands has a duty of care. This means that they will help you if you have a gambling problem. You can limit your visits, keep track of how often you gamble or even arrange an entry ban or exclusion.
Talk about it with an employee at the casino. They are happy to help you.
Loket Kansspel is the central support center in the field of gambling problems. They offer help and refer you to help and guidance in your area.
These services are free.
The AGOG is a self-help organization for gambling addicts and for people in a relationship with a person that has a gambling problem, that is to say: for partners, for parents and for other family members or friends of someone who gambles.
You can always visit your GP. They know who you can ask for help and can also refer you to addiction care.