Hi, i have changed my apple id in my ipad now i realised after changing the id many of my videos and photos are deleted in my ipad, already checked my icloud account as they were already not there just stored in ipad but not in ipad memory

Here are Apple’s support pages concerning update to your AppleID account and/or associated password - and the actions that you should complete after making any changes:

Change your Apple ID - Apple Support

What to do after you change your Apple ID or password - Apple Support

You should be aware that changing your AppleID is generally a bad idea - as all App, Service and Media purchases from Apple are forever associated with the AppleID from which they are purchased. If you elect to use a new AppleID account, you will lose them all - and will have to re-purchase if you wish to continue using them.

If you simply need to change the AppleID username (which is normally your primary email address), it is both possible and recommended that you simply update your existing AppleID account with the new email address. Doing so preserves all purchases associated with your existing AppleID account.

Whilst updating your primary email address (for sign-in to your AppleID account), you would be well advised to verify and update any secondary (recovery) email addresses and trusted telephone numbers - as these are essential for account recovery purposes should you ever become locked-out of your iPad and/or your AppleID account. It is recommended that you have multiple trusted telephone numbers (fixed landline and mobile) and secondary email addresses.

You can update your AppleID account from any web browser:

https://appleid.apple.com

As for recovering any photos or documents in your original AppleID/iCloud account, if previously uploaded to iCloud, you should be able to directly access them from a web browser:

https://icloud.apple.com

To do so, you’ll obviously need the AppleID and associated password for your original account. If these have also been forgotten, you should be able to recover them here:

https://iforgot.apple.com

To recover your credentials, you’ll need access to one of the following:

• Your primary email address mailbox that corresponds with the target AppleID
• Any of the secondary/recovery email addresses that should be configured for the target AppleID account
• Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with this AppleID

Unless you AppleID account has not been fully/correctly configured, or has been seriously neglected, recovery of the AppleID and password should not be difficult.

More information about recovery of your AppleID:

https://support.apple.com/en-us/HT201354

More information about recovery of your AppleID password:

https://support.apple.com/en-us/HT201487

I hope this information and guidance is helpful in resolving your difficulties.

You should NEVER change your Apple ID. Your iCloud services and all apps are tied to the original Apple ID they were tied to from the start.

Why did you feel you needed a new Apple ID? If you were concerned about security, you keep your Apple ID, but change your Apple ID Password.