Urgent help for bad dog needed!

Hello,
I have a small shitzuh that I rescued in Korea four years ago. She was a good dog until two years ago when she was bit in the park. She has progressively become more aggressive towards other dogs. For a long time it was just barking but recently she's turned very angry and impossible to walk. Ive read lots of books and seen a trainer but I dont know what to do and it keeps getting worse-yesterday she bit my friend's baby in the face! I have heard there is a behaviorist here in Seoul but I am a stay at home mom and unfortunately I dont have any extra funds for this. Can anyone help? I can trade for things and I bake cookies! The only other alternatives I see are rehoming her or getting her put down, both of which Im really not keen to do! Thank you.