I agree that ultimately the best path here is to talk to your mom.
In the meantime, here are a couple resources on managing separation anxiety (even though I 100% agree this shouldn't be on you):
https://www.amazon.com/dp/B001CSLJR2/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
https://www.amazon.com/dp/B005QD0Y34/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
And one on resource guarding:
https://www.amazon.com/Mine-Pratical-Guide-Resource-Guarding-ebook/dp/B06Y2GXSX3/ref=sr_1_1?dchild=1&keywords=Mine+Jean+Donaldson&qid=1603474770&s=digital-text&sr=1-1