Keep trying. Also, you might want to try some methods that increase shiny rate.
The current chance to find a shiny is 1/4096. This can be increased however if you take in account some various shiny methods.
Basically, you find Grubbin in the wild and then use an Adrenaline Orb. This will make it likely to call for a partner Pokémon. OHKO the Pokémon it calls and repeat the process. Pokémon that are called for help when you have a chain length of 70 through 255 get three extra rolls when determining shiny.
The Masuda Method is a method in which two different Pokémon from different regions can breed for increased shiny rate. The chances of the offspring being shiny is 6/4096.
If you have a shiny charm, the chances of finding a shiny in the wild goes to 3/4096. Note: Shiny Charm gains and the methods above do stack, so having a Shiny Charm is always a must. You can obtain the Shiny Charm by completing the Pokedex and talking to someone in the Game Freak office in Heahea City.
The Oval Charm, on the other hand, is a key item that increases the chances of hatching a shiny from an egg. There is no fixed chance. This is achieved by defeating a trainer in a battle in the Game Freak office.
Some sources may not be official, but I couldn't really find too much info: -_-
Hope I helped! :)