I forgot my iPhone X password

You will need to restore your phone and then reload your most recent backup. See here: https://support.apple.com/en-us/HT204306.

If you did did not make a recent backup while you had the data on your phone, then unfortunately that data will be lost. I have my phone and iPad set up for daily iCloud backup’s.

If they were very, very important to you of course you backed them up regularly, probably by setting up nightly automatic backups to iCloud. If the phone is disabled because you don't remember the password the only solution is to restore the phone to factory settings, then restore the backup that contains the very, very important content. See this Apple support link-->If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

You might also have chosen one of these methods to preserve your very, very important photos and videos:

• Enable iCloud syncing of photos (different from iCloud backups). To check log in to hthttps://icloud.com/photos.
• Enabled PhotoStream that copies your photos to your computer.
• Synced with a 3rd party archiving site, such as Google Photos, upthere.com, shutterfly.com, Nikon archive, canon archives, etc.
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If you forgot your Apple ID password - Apple Support