Help my sweet boy

My sweet cat, Laufey, has been diagnosed with heart failure at just 1 year old. He was brought into the veterinary hospital struggling to breathe and remained in a critical condition overnight. A few hours after receiving a different type of blood pressure medication, he perked up, was alert, and walking around. He is making progress, but still needs care from the cardiologist and a couple more nights at the hospital. It unfortunately is more money than I can afford and I desperately need help.