I believe you didn't download the Middle Eastern version, I advise you of following these steps to get the Arabic language in Photoshop and other Adobe applications.
From the Adobe Creative Cloud Desktop menu, click on All Apps to view a list of installed Adobe applications
Click the three ellipses shown beside each installed application
Choose Uninstall to remove the non-Arabic application
Once ALL installed applications have been uninstalled/removed, click on the “Account” icon found on the top-right corner of the Creative Cloud desktop application and choose “Preferences”
5. In the newly opened Preferences dialogue window, click on “Apps” in the left pane
6. Scroll down to the bottom of the window, from the “Default install Language” drop menu choose English يدعمالعربية in order to have Arabic support in Adobe applications, then click the “Done” button.
Now you may proceed to install Adobe applications once again.