Hi! My 8yr old female cat had major abcess surgery 2.5 weeks ago and is now reunited with her also 8 yr old sister. She is healing well with no complications, however, she is now very very reserved, quiet, and will not go by her sister at all. This is not her usual personality. She doesn’t seem like the same cat at all. She was opened up from her tail to her hind leg.. very scary. She seems to be eating and drinking. I’m very concerned.. opinions?