Also, there are ways to break SVT, called vagal maneuvers. One of them is called a valsalva maneuver. There's a guy on this board that is really good at explaining/using these, look for posts from Tom_h. He's very helpful.
For some people, alcohol triggers atrial fibrillation. In your case, what the ER doctor told you sounds like AF. To get back on track, you probably have to skip alcohol for a while, watch what you eat and drink to see if there are any other triggers. Eating foods that are rich in potassium and magnesium may help, and don't stress or stop exercising because that doesn't help either.
If only I knew how. It's a vicious cycle. No matter how many times I tell myself I'm fine the thought of having an svt attack getting out of control and needing to go to the ER for meds prevents me from doing damn near anything. Its actually put me into quite a depression reading others experiences online gives me the impression it will only get worse over time. Just waiting for the next attack constantly is ruining my life. Saposed to go to Vegas next month for 21st birthday, but petrified. Needing some sort of encouragement
Resistance to propranolol builds up fast and you have to keep increasing the dose to chase it. Propanolol is a great compound, one of the oldest drugs out there, but your body finds a way around it easily. Therein lies another bad can of worms, but that's what you'll need to address if you want to stay on the med. I've always backed off meds completely when this was my reality, and that worked out in the end for me, but everyone is different.
The SVT might be a very short run. I really hate the term SVT, because it's an umbrella term that can mean different causes depending on who you talk to. So when I hear someone say they had SVT I'm wondering what actually happened. Any tachycardia that arises in the atrium a.k.a SUPRA (above) Ventricular falls under SVT. There's quite a few etiologies for this (root causes).
And if you develop an anxiety issue over a fast heart rate, well good luck with that! Been there, done it. Talk about a feedback loop, yikes! Took me all sorts of time and effort to get past. It was like trying to get over PTSD. I would nip that in the bud if that's starting to happen to you.