Heart failure is a very scary sounding term when in reality means, the heart isn't pumping as well as the body needs. It isn't like a hard disk failure which is imminent, sudden and terminal. The heart is weak and stiff. You were dependent on alcohol - and alcohol is very much toxic to heart tissue. Modern medications work by reducing the strain on the heart, the amount it needs to work and reducing your blood pressure to make everything a bit better.I'm sure this was all explained to you in the hospital but sometimes big news means you forget most of it straight away.
Was this diagnosed with a blood test or echocardiogram?
At 37 you have a) completely trashed your body but b) have a chance to make radical changes so you have many years left in you. If you've had a clinical diagnosis of heart failure, then it will never usually be cured, but good management and you won't even know about it. I have diagnosed patients with heart failure, I manage many with heart failure, and I have looked after the palliative patients dying of heart failure.
Think of this as a massive, massive wake up call. If you continue drinking, I'd say you have much less than 10 years left in you. On the flipside, reduce your alcohol intake slowly rather than cold turkey.
ps. also really keen to hear about your liver function blood tests