Unfortunately it isn't just in the USA. It's all over the world. Until people stop treating cats as pests who are only here to help eradicate other pests (mice, rats), and start treating them with the same respect they do dogs the problem isn't going to change.
Thing is -
you can change things in your neck of the woods. There are many low cost s/n clinics in the US. Hopefully there is one near you that would be willing to help you. Yes, you will have to do the work. Yes, it is possible. More than possible.
Many people have done it. Most with little money to spend. All you need is perseverance and determination. And a live trap. Maybe once people see what you are doing they will be willing to step up and do their part.
SCM gave you a great website to check out. It will help teach you about t/n/r and programs that are available to you. SCM has also been instrumental in cleaning up her area.
Love4himies also gave you some great advice. Beg, borrow, do what you can that is legal. Try writing to some pet companies and see if they would be willing to donate some food.
Here are a couple of sites for building low cost shelters for the kitties for over the winter. I'm sure there must be a spot in your area where you can put them out of the way and protected from severe weather.
http://www.indyferal.org/index.php?page=shelters
http://www.neighborhoodcats.org/HOW_...WINTER_SHELTER
In the winter it would be near impossible to feed canned food if you are in a very cold region. But you could put out dishes of dry with some warm water available (to be changed regularily), and give an occasional can (or a few) of tuna, sardines, or some other fishy cheaper foods. A big bag of dry food is economical and will last for a while.
Good luck and thank you for caring.
