Well after it's episode under the bed I took it to the vets down the road. The Vet only had a quick look at her, her teeth (brave woman), felt her head, looked at her paws. Took an xray. Without looking at the xray she reckon at some point in her life she has been walloped on the head, there's a slight hard spot on her head, the same side where the chunk is missing from her ears. She can't say for certain until the xrays come back (computer problem) so will call back with blood and xray results.
Said that is quite likely but not deff' that this is the result for her skattyness.
I dunno WTF to do. Need time to think.
Part of me says give her to my grandparents where she can live in a very rural setting in a garage, getting fed real meat every day like their previous cats, the other part of me wants a cat and I feel like ive failed. I dont agree on getting animals to get rid of them when theyre too much and it is exactly what ive done