Please help me my cat very sick

My cat it’s  being sick for the past 3 days . I need to take him to the vet but I know how much expensive vets can be .

His name kiwi I have him for the past 17 years . He stop eating for the past 2 days and stop drinking water .

I haven’t work for the past 8 month because covid I don’t have much money save :( and it’s breaking my heart I won’t be able to help me . I will make appointment today with the vet and see how much will be for his test and etc . I know from past experience that it be a lot . I’m notready to lost my cat :(  please help me with anything you can