Wk 8 of Triple Therapy: Experiencing Severe Shortness of Breath

I am really worried. Went out this evening, just to walk the dog, with my husband. (It was a short walk.)

My husband got so out of breath I thought he was going to collapse again. He said his chest felt really tight, and he could hardly breath. He also said it happens often, but he doesn't want to tell the doctor. He's afraid he'll stop the treatment. I'm afraid he is going to have a heart attack.

I don't know what to do...