I was really struggling with SOB a few months before surgery, like daily. 1 month before surgery it got really bad, couldn't talk without getting SOB, couldn't lay flat on my back. Sitting watching TV I would feel like I needed to gasp for air and when I did I couldn't get a good breath. Now 5 weeks post op it has gotten a lot better. I still tire easily but better than before surgery that's for sure.
I hate to sound like mister obvious but the only thing that helped me was the surgery. I know your on the waiting list, I was on a waiting list for a month and I didn't think I was going to make it to the surgery date. Nothing I did before surgery helped with the SOB, one cardiologist told me a year before surgery that I would know when it was time, the problem we have is mechanical it doesn't come and go, it's constant. When its time you will feel symptoms all the time. That's basically what happened to me.
If it gets really bad rubywhistle I would recommend going to the emergency.