I think you should admit to your wife that you were fired, after all, she is your wife. I think you have lived together for many years and have already had many failures together, and this failure you should go through with your wife. As far as I'm concerned, quitting your job isn't so scary, it opens up new avenues, you can find a more promising job. As for betting, it's a good idea, you can actually earn something, you can read this article:
https://ponbee.com/betting-on-football-in-2022/ . I'm sure you will learn more from it, but still my advice is to tell everything to your wife, she will find out one day anyway.