Sounds like the magickal output attracted some kind of parasite. It’s probably feeding off your pain in some manner and possible holding her away until it’s has it’s fill. What do you practice to maintain a clear space and ward off unwanted entities so far?
We have more tutorial and experiences poste by members here: being skilled in banishing so you can immediately repel such things instead of having to put up with them until they’re done is am important aspect for mages that work with entities, but often not mentioned in books focusing on a technique and not on setting you up for success with this kind of basic tool.