Hello Jansdad,
You say your wife had regained trust in you? Presumably that means that this has happened in the past as well at some stage? Why lie to her? Honesty would mean she could help you be more accountable for the rest of your money. If you were both planning on investing this money in something then presumably she will find out that the money is missing at some stage anyway won’t she? Trying to keep things covered up can in itself send people back to gambling as they try to replace lost money.
How about barriers? where do you normally gamble? If it is online then you can get a blocker for your PC. if it’s at a casino then you can get self excluded.
Keep posting and let us know the positive steps you are taking.