Hey Maggie Ardito,
You can try this out: Housekeeping - beta
It will tell you how many credits you are using to host what content. You may be able to find some layers that you no longer need that are chewing up credits.
The credit usage is generally hosted feature layers so if you can minimize the size of those layers by removing unnecessary data it can really help with the credit usage.
If the above don't help please reach out to me and I can help you out more or can help you interpret the results.
Thanks
Ben
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