I agree with Dr. Coyner. Not eating or drinking is a much bigger problem than the licking. Perhaps we don't have the whole story here, but let's have a veterinarian do an exam to uncover the cause of the lack of appetite and thirst.
As for the hyper and licking, I have seen this in recently shaved cats. It feels very strange to them to suddenly not to have all that normal fur. In addition if there are a couple of nicks you can see, and there are probably many you cannot see. That alone will cause her to feel itchy, unsettled and her reaction will be to become hyper active / lick etc.
If that is the case, it will go away slowly. But you should focus on the eating and drinking right now.
A 10kg cat is a 22# pound cat, which is certainly not underweight, but is obese, so I am assuming this is a typo. If your cat is not eating or drinking, then this is an emergency, and your cat should go to the veterinarian ASAP. The excessive licking may be due to fleas, allergies, or anxiety (or a combination), and your veterinarian can examine her to tell you the best course of treatment.
Kimberly Coyner, DVM