I understand that 'BIG' means different to different individuals. Here by 'BIG' I mean life-changing money (bigger than 20x of your monthly income).
1. Let the money sit in your bank account (wallet) for at least one month. It will allow you to settle down your heightened emotions. Just let the amount sit and do not do anything with it for at least one month.
2. Go on a low-cost, week-long vacation with your family and friends (do not tell anybody about your winnings; do not boast) immediately. It will help you make your relationships stronger and will certainly help in doing step 1.
3. Do not change your lifestyle immediately, as it will help you to remain disciplined, which will eventually help you out to earn even more.
4. Consult a certified financial consultant and invest in a diversified portfolio other than gambling, probably for the long term, at least 80% of your winnings.
5. If your winnings are even greater and allow you to quit your job, then use your time to learn finance.
If you have any suggestions feel free to addon.
1.Let it sit for 1 month which it won't really be giving out the guarantee that you won't be spending it again in gambling.It will still have the possibility that you would be spending it all.
2. Spending up some time with your family with your winnings is a good action to make yet spending up something for family is always been a good thing but it should be in moderation in comes on spending money.
3. Changing life style that isn't that in line with your source of income is really just suicide. Don't try to make yourself get in line with other people who do have much better situation that you because we do have different status in life.
4.If the amount is significant then this is the time you do consider on getting one.
5.Quitting your job isn't recommended and also it's really that boring if you won't be doing something despite of having a huge money or sustainable income, but who doesn't like to work 8-5 forever?