In conclusion, if you are already having a rough time on playing same game over and over despite you have a good experience on it before. Trying new games to you and taking break will help you to snap out of your losing streak because chasing losses usually make us trap on our losses.
In your case, how do you approach when you are on losing streak so badly on specific game. Does changing game works for you?
Previously I don't know if someone has told you this. That it doesn't all of the time work in this way as it did for you by virtue of your changing game from blackjack to slot. Someone somewhere could have tried this strategy after going through series of losses and still didn't change the outcome to any win. It's same as someone having a rough time with a particular slot machine at the casino after several session and then decides to change to use a different slot machine and still didn't get a smooth outcome.
By some way of luck we could chose to change our position about a game and hit a win but this is not guaranteed as it has the propensity to lead to further loss. The safe option to fall on when the loss has become a continuous one after several session is to take a break. Taking a break is a powerful strategy in preventing unwarranted losses. That's what I do when the streaks are not going in my favor. I don't push it.