Cat not eating

my friends cat (Adult) hasn't eaten for 20 days, and also vomiting. and now he can't walk. what can my friend do to save his cat? He's in Gaza, and there is not vets around.. the situation is so dire there.

May I start by saying how sorry I am that your friend is in such a situation and are unable to get help for their cat.  It's most of our nightmares to stand by watching loved ones suffering, whether they are animals or people.   This cat may be in Gaza, but it would be the same if they were in Wales or America or even in my living room; without the facility to examine an animal (and probably to do tests on it, because one vomiting, dehydrated cat often looks clinically like another before doing tests / clinical exams to find out why) it is difficult to pinpoint the cause of the vomiting or to know how to try to stop it.  Furthermore, without the facility to put fluid back into a vomiting animal's circulation (by which I mean a sterile drip or possibly sterile sub cutaneous fluid as a very poor second-best) they can also be or become dehydrated, which is dangerous.  Uk Vets are used to having the correct medical supplies to hand and knowing how to use them - it is a large part of the reason we can successfully treat sick animals.  We would simply not attempt to treat dehydration in a continually vomiting cat, that has not eaten for such a long time, in the home.  Assuming that medicine is not an option, many animals will appreciate being somewhere they feel safe, warm but not hot,  calm, with tiny, frequent amounts of food offered but not forced and water as they need it.   I have no magic answer to this problem and from my limited understading, which may not be ask i am picturing it, but I worry that the patient may not get better if veterinary help is unavailble.