Help my sweet kitty, Mika

My little kitty Mika has been feeling very unwell. About a week ago, she started acting a little funny. A few nights later she was straining to poo and there was a little blood in it too. I took her to the vet and got some medicine, and eaiser to take food. If this doesn't work, the surgery and medical care will cost about 2000 dollars. If I cannot afford this, then I may even consider putting her down to save her from any more pain. So please, even its just a little, it would mean so much to Mika and the world to me. Thank you for reading. Every bit counts.