You should absolutely engage a criminal defense attorney immediately. You should not make any statements to the police or go to the police station without an attorney present. I know I am reinforcing what others have written, but it is very important that you listen to this.
If your case has been continued for 3 months, then he may not even have the information he needs to discuss it with you. He undoubtedly has cases that are on trial or in hearing now which he must deal with first. You might as well enjoy your time as nothing will be decided until you go back to court.
If the police were not involved and you were not arrested, this event will cause no problem with your visa. They will probably send you a letter demanding some funds, but they do not usually take it any further than that.
You will definitely need the receipt from the casino if you filled out a tax form when you won. If you didn't win in a lump sum you will need to prove that you were there and were winning. You should definitely talk to a criminal defense attorney before you make any statements to anyone else.
You don't mention if you are a Canadian citizen. However, a warrant may well show up when you travel and cross the border. You should try to clear it up before you leave, speak with a criminal attorney.