I don't understand why my child tax credit is only 500 when last year it was 1500.

There are a few reasons why you might get the Credit for Other Dependents rather than the Child Tax Credit. 
Most common are:

• Your child is now 17 years or older
• Your child is no longer considered a qualifying child, but is considered a qualifying relative dependent
• Your child has an Individual Tax Identification Number (ITIN), but doesn't have a Social Security number

Click to see more information about the requirements for claiming the Credit for Other Dependents.

Also in tax year 2021 the rules for Child Tax Credit were relaxed by covid relief legislation and available to tax payers without earned income. 

For tax year 2022, we are back to the standard rules and the Child Tax Credit is:

• non-refundable
• $2,000 a year per child
• only available to taxpayers with at least $2,500 in earned income
• only available up to the limit of your tax liability shown on the return

So if there is not at least $2,500 in earned income and no owed taxes on income, the return will not qualify for the credit this year.